Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
EC and Estonian Centre of Excellence Biannual Report 2004/2005 Tartu 2006 Prepared by H. Jõgi, M. Kirm and H. Käämbre Front cover: Blue fluorescent protein Courtesy K. Mauring Back Cover: ZrO2 micro-tube self-assambled from a nanostructural film V. Reedo, M. Järvekülg Courtesy Estonian Nanotechnology Competence Center Copyright Tartu Ülikooli Füüsika Instituut, 2006 ISSN 1406–7927 Tartu Ülikooli Kirjastus www.tyk.ee Tellimus nr 397 CONTENTS Füüsika Instituut aastail 2004/2005 ............................................. 5 Institute of Physics in the years of 2004/2005 .............................. 10 1. Organization and Personnel .................................................... 1.1. Structure.......................................................................... 1.2. Supervisory Board ........................................................... 1.3. International Advisory Board of the Institute .................. 1.4. Directorate...................................................................... 1.5. Directorial Board ............................................................ 1.6. Personnel ........................................................................ 17 17 18 19 19 20 20 Estonian Nanotechnology Competence Centre............................ 26 2. Grants/Contracts and Cooperation Partners ........................... 29 3. Research Highlights ................................................................ Difference fluorescence line narrowing – an effective selective spectroscopy tool for studies of complex molecular systems .............................................................. Probing anomalous ZZȖ and ZȖȖ couplings in e+e– ĺ ZȖ with polarized initial beams ............................................... Cuprate superconductivity caharcteristics on the doping scale. A simple model......................................................... How small a packet of photons can be made? ......................... Multiphoton processes in intense laser fields........................... 35 35 41 47 56 60 4 • Biannual Report 2004/2005 Decay of Anion and Cation Excitons into Frenkel Pairs and Defect Triplets in LiF Single Crystals ..................................... 62 Resonant inelastic scattering at the F 1s photoabsorption edge in LiF ........................................................................ 67 4. Scientific Report ..................................................................... 72 5. Publications ............................................................................ 128 6. Talks and Posters at Conferences ............................................. 157 7. Dissertations Prepared at the Institute..................................... 180 8. Graduation Theses Prepared at the Institute ........................... 182 9. Scientific Meetings Organized ................................................ 184 10.Visits to Research Centres Abroad .......................................... 186 11. Visitors .................................................................................. 195 12. Pedagogical Activities............................................................. 12.1. Lecture courses at the University of Tartu..................... 12.2. Supervising of PhD theses (postgraduates, doctoral level) of the University of Tartu.................................... 12.3. Supervising of MSc theses (postgraduates, master level) of the University of Tartu............................................. 198 198 200 201 13. Awards .................................................................................. 203 14. Acknowledgements................................................................ 205 FÜÜSIKA INSTITUUT AASTAIL 2004/2005 1947. a. asutatud ja sügisest 1997 Tartu Ülikooli koosseisus oma tööd jätkav Füüsika Instituut on peamine füüsika ja selle sidusalade uurimiskeskus Eestis. 2005. a. lõpus töötas instituudis täiskohaga teaduri, vanemteaduri või laborijuhatajana ligi seitsekümmend teaduskraadiga koosseisulist teadustöötajat. Neile lisandub poolsada teadustööd teenindavat töötajat: raamatukogu, peenmehaanika töökoja, heeliumit veeldava külmajaama ning majandusosakonna personal. Veel on meie tegevusse lülitunud paarkümmend tähtajaliste lepingute ja grandiprojektide täitjat. Käesolev raamat jätkab Tartu Ülikooli Füüsika Instituudi trükis avaldatud aruannete traditsiooni. Ta järgib ka eelmise 2002/2003 aruande vormi ja kujundust. Esimeses osas tuuakse andmeid instituudi struktuuri, juhtorganite ning personali kohta, samuti esitatakse saadud uurimistoetuste ja lepingutööde nimistud. Järgnev osa “Research Highlights” pakub lugejaile loodetavasti enim huvi, kuna siia on koondatud lühiartiklid uurimisteemade valdkondade esileküündivamate tulemuste kohta. 4. osa “Scientific Report”, aruande põhiosa, annab ülevaate instituudi uuringute olulisimatest tulemustest sihtfinantseeritavate teemade lõikes. Järgnev on juba pigem formaalstatistiline kokkuvõte: publikatsioonide, konverentsiettekannete ning kaitstud väitekirjade nimistud, kokkuvõte instituudi poolt korraldatud teadus-kokkutulekuist, andmed instituudi töötajate välislähetustest ning meie maja külastanud välisteadlastest, ülevaade instituudi teadurite panusest TÜ õppetöösse jmt. 6 • Biannual Report 2004/2005 2004. a. aprillini jätkas instituut tööd Euroopa Komisjoni tippkeskusena ja kuni 2007. a.-ni jätkab ka Eesti tippkeskusena. Aastad 2004 ja 2005 olid instituudile väga edukad. Eesti Vabariigi preemia pikaajalise teadustöö eest anti 2004. aastal meie teenekale kolleegile akadeemik Tšeslav Luštšikule, preemia viimaste aastate teadussaavutuste eest said täppisteaduste alal prof. Nikolai Kristoffel (2004) ja tehnikateaduste alal (2005) kollektiiv, kuhu kuulusid ka Rünno ja Ants Lõhmus. 2004. a. lõpus õnnestus edukalt käivitada Ettevõtluse Arendamise Sihtasutuse (EAS) poolt rahastatav NanoTAK. Aruanne selle tegevusest esimese aasta jooksul on lisatud ka käesolevasse kogumikku. 1. juunil 2005 alustas tegevust materjaliteaduse ja materjalide tehnoloogia doktorikool, kus partneriteks on Füüsika Instituut, füüsika-keemiateaduskond, TTÜ ja KBFI. Enamuse meie maja doktorantide rahastamine toimubki läbi eelpoolnimetatud doktorikooli. FI oli edukas ka teaduse tippkeskuste infrastruktuuri rahastamise taotlusvoorus, mida kureeris samuti EAS – rahvusvahelise komisjoni hinnangul osutus FI projekt kümne taotluse esitanud tippkeskuse seas parimaks. Sellega kaasnes 17,8 mln kroonine toetus aparatuuri kaasajastamiseks ja infrastruktuuri renoveerimiseks, millest suurem osa leiab kasutamist 2006. a. Kahjuks ei käinud meie käsi nii hästi teaduse infrastruktuuri programmist rahade ühistaotlemisel osana konsortsiumist koos ülikooli mitmete teiste struktuuriüksustega. Meie taotlus ületas küll vajaliku hinnangukünnise, kuid rahajagajal olid vahendid selleks ajaks juba otsa lõppenud …(!) Edukas koostöö on instituudil olnud mitmete suurte ja väikeste firmadega. 2005. a. juunikuus kirjutasime alla lepingu elektroonikahiiglasega “Samsung” plasmateleviisorite paneelide materjalide uurimiseks. Koostöö sujub hästi ja loodetavasti saab edukatest tulemustest kirjutada järgmises kogumikus. Samuti teeb instituut uuringuid ka Eesti firmadele ja sihtasutustele – alla on kirjutatud lepingud Keskkonnainvesteeringute Keskusega ja Tallinna Sadamaga naftareostuse detekteerimismeetodite väljaarendamiseks. Eesti väikefirmadega on tihe koostöö NanoTAK-i raames, samuti jätkub konstruktiivne Füüsika Instituut • 7 koostöö Tartu Teaduspargiga. 2005. a. sügisel tähistasime peahoone valmimise kolmekümnendat aastapäeva, avasime pidulikult uue multimeedia õppeklassi ja kaasaegselt sisustatud pinnafüüsika laboratooriumi, millele aparatuuri hankimiseks andis juba 2001. a. esimese “seemne” Rootsis tegutsev Erna ja Victor Hasselbladi fond. Aasta 2005 kuulutati UNESCO poolt füüsika aastaks, selle raames võttis instituut endale ülesandeks tegelda füüsika ja üldse teadusliku maailmavaate populariseerimisega. Ajakirja “Horisont” 2005. a. igas numbris ilmus üks või mitu artiklit instituudi töötajate sulest, milles autorid tutvustasid oma teadustegevust ja antud teadusala probleeme laiemalt. Selline “dessant” äratas ka laiemat huvi ja FI pälvis 2006.a. alguses selle artikliseeria eest MTÜ Loodusajakirja aastapreemia “Seest suurem Eesti”. Füüsika populariseerimisel olid väga tublid ka meie nooremad kolleegid, doktorandid ja magistrandid, käivitades Eesti Televisioonis hommikused “Terevisiooni” füüsikakatsete minutid. Samuti osalesid nad väga aktiivselt “füüsikabussi” käivitamisel ja selle aastaringsel käigushoidmisel. Selle tegevuste eest pälvisid nad Haridus- ja Teadusministeeriumi teaduse populariseerimise esimese preemia. Ajast aega on meie ja Tartu Ülikooli füüsikaosakonna tegevus olnud tihedalt põimunud. Enamik ülikooli füüsikaprofessoreid on tulnud instituudist ja jätkavad oma uurimistööd meie laborites. 2005. a. lõpu seisuga töötas instituudis siinsete teadlaste juhendamisel üle kuuekümne üliõpilase, magistrandi ja doktorandi. Instituut on ikka püüdnud aiva agaramalt osaleda ka auditoorses õppetöös. Et veelgi tõhustada meie teadlaste panust selles tegevuses, loodi Tartu Ülikooli füüsikaga tegelevate institutsioonide katusorganisatsioon Füüsikum. Õppetöö parema koordineerimise huvides avasime instituudis õppedirektori ametikoha. Detsembris 2005 moodustati teadusnõukogu otsusega laboreid ühendav materjaliteaduse osakond, et senisest veelgi edukamalt teadus- ja arendustöid läbi viia. Teaduse riigieelarveline rahastamine toimub Eestis peamiselt sihtfinantseeritavate teemade kaudu. Need hõlmavad suhteliselt laiu 8 • Biannual Report 2004/2005 valdkondi ja määratakse kindlaks kuni viieks aastaks. Sedakaudu sai instituut 2004. aastal 13,2 mln krooni ja 2005. aastal 14,4 mln krooni sihtsuunitlusega raha. Praegune rahastamisperiood algas 2002. a. ja lõpeb käesoleva aastaga. Ees seisab tõsine ülesanne pakkuda välja uued atraktiivsed sihtsuunitlusega teadusteemad järgnevaks perioodiks. 2004/2005 olid meie sihtfinantseeritavad teemad järgmised: 1. Valgustundlike materjalide laserspektroskoopia ja nende rakendused (teema uurimisjuht prof. J. Kikas) 2. Nanostruktuursed materjalid (dr. K. Haller, dr. A. Rosental alates 2005) 3. Biofüüsikalised elementaarprotsessid ja nende dünaamika (prof. A. Freiberg) 4. Eesti keskkonna radioaktiivsus ja kiirgusdoos (dr. E. Realo) 5. Aine süvastruktuuri teooria (prof. V. Hižnjakov) 6. Laserifüüsika ja laseroptilised tehnoloogiad (prof. P. Saari) 7. Fundamentaalnähtused laia keelutsooniga materjalides ja nende rakendusperspektiivid (prof. A. Luštšik). Nende teemade järgi on liigendatud ka käesolev aruanne. Aastal 2004 (2005) on Instituut saanud kasutada veel järgnevaid summasid (mln kroonides): infrastruktuuri rahastamine 4,8 (5,1); Eesti Teadusfondi grandid kogusummas 5,3 (6,7); Eesti tippkeskuse finantseerimine 3,4 (3,0) ja mitmed tööstus- ja mittetulundusühingute lepingud. Instituudi teaduse finantseerimise reale lisandus 2005. a. baasfinantseerimine 4,0 mln krooni, mida direktor saab kasutada uute uurimissuundade avamiseks ja teemade toetamiseks, infrastruktuuri arendamiseks või välis- ja siselepingute kaasfinantseerimiseks. Teadus- ja arendusasutuse baasfinantseerimise mahu algoritmi üheks olulisemaks teguriks on ISI andmebaasis kajastuvate asutuse töötajate teadusartiklite arv. Et instituudi teadlaste osalusega artiklite arv on viimastel aastatel näidanud mõningast langustrendi, otsusta- Füüsika Instituut • 9 sime stimuleerida oma parimaid publitseerijaid nn publitseerimispreemiatega. Esimesed kokkuvõtted tegime 2005. a. publitseerimistulemuste alusel, kavas on seda jätkata ka edaspidi. Füüsika Instituudis kasutada olnud summaarne rahamass oli 2004. a. 36,7 mln kr ja 2005. a. 40,3 mln kr. Kuid see ei hõlma veel kõiki kasutatud summasid. Kõikidest meie uurimistööde rahastamistest polegi võimalik täpset ülevaadet saada, sest mõnede projektide reisitoetused, toetused uurimistöödeks väljaspool Eestit jmt on sageli kaetud väismaiste uurimiseralduste arvelt. Kahe siin käsitletava aasta uurimistulemused on avaldatud kokku 246 publikatsioonis, kaasa arvatud 140 artiklit eelretsenseeritavates ajakirjades. Meie teadurid osalesid 116 teadusnõupidamisel, neist 89 olid rahvusvahelised. Kokku esitati 235 ettekannet (112 suulist ja 123 posterit). Mõningaid lisafakte Füüsika Instituudist ja kontaktandmed on leitavad internetisaidist http://www.fi.tartu.ee/ ning mõistagi ka instituudiga otse ühendust võttes. Kõik on selleks teretulnud! Ergo Nõmmiste, direktor INSTITUTE OF PHYSICS IN THE YEARS OF 2004/2005 The Institute of Physics (IPh), founded in 1947 and since the autumn of 1997 functioning as a R&D institution of the University of Tartu, is the main research centre of physics and associated fields in Estonia. By the end of 2005, about seventy permanent research workers with scientific-degrees were employed at the Institute as fulltime research fellows, senior research fellows or heads of laboratories. In addition, there are about half a hundred research-work-assisting employees, such as library workers, precision-mechanics technicians, cryogenic plant specialists and economics department personnel. There are also some twenty persons involved in our activities on the basis of temporary contracts and grant projects. This booklet continues the tradition of the scientific reports of the Institute of Physics of the University of Tartu published so far. It also follows the style and format of Biannual Report 2002/2003. The first section contains data about the structure of the Institute, its management bodies and personnel as well as the lists of the bestowed science grants and contract works. The following section “Research Highlights” is supposedly the most interesting one for the readers, as here are concentrated short papers about the most remarkable results of the research areas. Section 4, “Scientific Report”, the basic part of the report, presents a survey about the most essential results within the research topics supported by targeted financing. What follows is more or less a formal-statistical summary: lists of publications, conference reports and the defended theses, a summary of the scientific conventions organised by the Institute, data about the Institute of Physics • 11 assignments of the Institute’s researchers abroad, and about the foreign scientists who have visited the Institute, a survey about the contribution of our research fellows to the Tartu University study courses, etc. Until April 2004, the Institute continued its work as the European Commission-designated Centre of Excellence and up to 2007 it will continue as the Centre of Excellence of Estonia. The years of 2004 and 2005 were very successful for the Institute. In 2004, a state reward of the Republic of Estonia was bestowed to our deserving colleague Academician Cheslav Lushchik for a long-time research work, rewards for the recent years research achievements were also granted to Professor Nikolai Kristoffel (2004) in exact sciences and to a technical sciences group including Rünno and Ants Lõhmus (2005). In the end of 2004 we managed with a successful activation of NanoTAK, financed by Enterprise Estonia (national support system for entrepreneurship in Estonia). A report about its activities during the first year has also been included into the present collection. On June 1st 2005, the Doctoral School of Material Science and Material Technology started its activities, where the partners are the Institute of Physics and the Faculty of Physics and Chemistry (University of Tartu), Tallinn University of Technology and National Institute of Chemical Physics and Biophysics (NICPB). The financing of most of our doctoral candidates takes place via the aforementioned Doctoral School. The Institute of Physics was also successful in the call for proposal to finance the infrastructures of the Centres of Excellence, that was also governed by Enterprise Estonia – according to the evaluation of an international committee the project by IPh appeared to be the best among ten excellence centres contender projects. The support money totalled 17.8 MEEK, which is meant for modernising the equipment and for renovation the infrastructure, most of which will be used in 2006. 12 • Biannual Report 2004/2005 Regrettably, we were not so lucky with our joint application of financial support for the science infrastructure programme, which we submitted together with a number of other structure units of the University of Tartu as a part of the consortium. Although our application exceeded the required evaluation level, by that time the provider’s money had just run out ... (!) The Institute of Physics has had a successful co-operation with a number of large and small companies. In 2005, we signed a contract with the electronics giant “Samsung” on the investigation of materials for plasma TV panels. This co-operation proceeds well and hopefully its successful results can be reported in our next collection. The institute also makes investigations for the Estonian companies and foundations – contracts have been signed with the Centre of Environmental Investments and Tallinn Port for developing the methods of detecting oil pollutions. Within the NanoTAK IPh has a close co-operation with the Estonian small companies, a constructive co-operation is going on also with Tartu Science Park. In the autumn of 2005, we celebrated the 30th anniversary of the opening of our main building, inaugurated a new multi-media study class and a modern surface physics laboratory, for which the first “seed” for procuring the equipment was given by Erna and Victor Hasselblad Foundation in Sweden already in 2001. The year 2005 was declared by UNESCO the year of physics. Within these frames the Institute of Physics made a commitment of popularising physics and the scientific outlook on life in general. In 2005, in each edition of the magazine “Horisont” there appeared one or several articles by the research fellows of IPh, in which the authors introduced their scientific activities and the relevant scientific field problems in general. Such “landing” generated also a wider interest and in the beginning of 2006 IPh was awarded for this articles series an annual prize of the non-profit Nature Magazine (MTÜ Loodusajakiri) “Estonia – bigger inside” (“Seest suurem Eesti”). In popularising of physics also our younger colleagues, doctoral Institute of Physics • 13 candidates and master’s candidates were very enthusiastic, activating in the Estonian morning TV (“Terevisioon”) programme the minutes of physics demonstration experiments. They were also very active in introducing „the physics bus“ and took care for its year-round running. For these activities the Ministry of Education and Research rewarded them with the first prize for popularisation of science. From times on our activities have tightly been interweaved with those of the Department of Physics of the University of Tartu. Most of the physics professors of the university have come from the Institute and they are continuing their research activities in our laboratories. As of the end of 2005, more than 60 students, master’s candidates and doctoral candidates worked in our institute under the supervising of our scientists. The Institute has always tried to be ever more actively involved in the auditory study work. To make our scientists contribution in these activities more efficient Füüsikum, a shelter organisation of the institutions dealing with physics, was founded. To ensure a better co-ordination of the study work we introduced a study dirctor post in the institute. In december 2005, the material science department was founded by the decision of Scientific Council, the aim of which is to carry out more succesfully research and development activitities bringing different laboratories together. The budgetary financing of research takes mainly place via the target-financed topics. These topics cover relatively broad fields and these are fixed for up to five years. By this way the Institute received a targeted financing in the amount of 13.2 MEEK in 2004 and 14.4 MEEK in 2005. The present financing period started in 2002 and it will end with this year. IPh confronts a serious task of proposing new attractive target-financed research topics for the next period. 14 • Biannual Report 2004/2005 In 2004/2005, our target-financed topics were as follows: 1. Laser spectroscopy of the light-sensitive materials and their applications (leader of the project Prof. J. Kikas) 2. Nanostructured materials (Dr. K. Haller, Dr. A. Rosental from 2005) 3. Biophysical elementary processes and their dynamics (Prof. A. Freiberg) 4. Radioactivity and radiation dose in Estonian environment (Dr. E. Realo) 5. Theory of the fundamental structure of the matter (Prof. V. Hižnjakov) 6. Laser physics and laser-optical technologies (Prof. P. Saari) 7. Fundamental phenomena in wide-gap materials and their prospects of application (Prof. A. Lushchik). The present Report has also been built up according to these topics. In 2004 (2005), the Institute has had a possibility of using also the following finances (MEEK): financing of the infrastructure 4.8 (5.1); Estonian Science Foundation grants in total 5.3 (6.7); financing of the Estonian Centre of Excellence 3.4 (3.0), and a number of industry and non-profit organisations contracts. In 2005, the the Institute’s science financing line was complemented by 4.0 MEEK of base financing, which can be used by the director for introducing new investigation trends and for supporting new topics, for developing the infrastructure or for co-financing international and internal contracts. One of the most essential factor of the algorithm of the research and developmental institution’s base financing amount is the number of scientific publications by the institution’s researchers reflected in the ISI data base. As the number of the publications with the participation of the Institute’s researchers has in recent years indicated some lowering tendency, we decided to stimulate our best authors with the so-called publication bonuses. The first publications-results- Institute of Physics • 15 based summaries were made in 2005 and these are to be continued also in future. The total amount of money at the disposal of the Institute of Physics in 2004 was 36.7 MEEK and in 2005, 40.3 MEEK. However, this does not comprise all the money used. In fact, it is not possible to get an exact survey about the financing of all our research works, as the travel grants of some projects, the research grants abroad, etc. are often covered from the foreign research allocations. The research results of the two years surveyed here have been publicized in total in 246 publications, including 140 articles in preedited magazines. Our research fellows participated in 116 scientific conventions, 89 of which were international. In total 235 reports were presented (112 oral ones and 123 posters). Some additional information about the Institute of Physics and the contact requisites can be found from the web page http://www.fi.tartu.ee/. Any direct contact with the institute is most welcome! Ergo Nõmmiste, director 1. ORGANIZATION AND PERSONNEL 1.1. Structure Institute of Physics, University of Tartu Riia 142, 51014 Tartu Estonia Phone: +372 7428 102 Fax: +372 7383 033 E-mail: [email protected] http://www.fi.tartu.ee 18 • Biannual Report 2004/2005 1.2. Supervisory board (The Scientific Council of the Institute) 1. Ergo Nõmmiste, PhD, director of the Institute (chairman) 2. Marco Kirm, PhD, research director of the Institute (vicechairman) 3. Ilmar Ots, PhD, senior researcher (elected vice-chairman) 4. Ene Ergma, DSc, member of the Estonian Acad. Sci., President of the Parliament of Estonia 5. Arvi Freiberg, DSc, head of laboratory, prof., University of Tartu 6. Vladimir Hizhnyakov, DSc, member of the Estonian Acad. Sci., prof. emer., senior researcher 7. Raivo Jaaniso, PhD, senior researcher 8. Arvo Kikas, PhD, head of laboratory 9. Jaak Kikas, PhD, prof., University of Tartu 10. Rein Kink, DSc, senior researcher 11. Nikolai Kristoffel, DSc, prof. emer., University of Tartu 12. Henn Käämbre, DSc, assistant director of the Institute 13. Aleksandr Lushchik, DSc, head of laboratory, prof., University of Tartu 14. Vitali Nagirnyi, PhD, senior researcher 15. Kaido Reivelt, PhD, director of studies of the Institute (from 01.06.2005) 16. Arnold Rosental, PhD, senior researcher 17. Peeter Saari, DSc, member of the Estonian Acad. Sci., head of laboratory, prof., University of Tartu 18. Matti Selg, PhD, senior researcher 19. Ilmo Sildos, PhD, head of laboratory 20. Aleksei Treshchalov, PhD, head of laboratory 21. Tõnu Viik, DSc, vice-director of the Tartu Observatory (Hudo Jõgi, PhD, assistant director of the Institute (secretary)) Organization and Personnel • 19 1.3. International Advisory Board of the Institute Prof. Hans G. Forsberg, ex president of Royal Swedish Academy of Engineering Sciences and of Council of Academies of Engineering and Technological Sciences of Sweden Prof. Rienk van Grondelle, professor of biophysics, the Free University of Amsterdam, the Netherlands Prof. Dietrich Haarer, professor of experimental physics, University of Bayreuth, Germany Prof. Maurice Jacob (chairman), former head of the Division of theory of CERN, ex president of the European and French physical societies, member of the advisory committee of “Physics Today”, Switzerland Prof. Tõive Kivikas, ex president of the company Studsvik and Estinvest Foundation, Sweden. 1.4. Directorate Director Ergo Nõmmiste, PhD +372 738 3039 e-mail: [email protected] Research director Henn Käämbre, DSc (up to 30.06.2004) Marco Kirm, PhD (from 01.07.2004) +372 742 8493 e-mail: [email protected] Director of studies Kaido Reivelt, PhD (from 01.06.2005) +372 7383 028 e-mail: [email protected] 20 • Biannual Report 2004/2005 Assistant director Henn Käämbre, DSc Assistant director Hudo Jõgi, PhD Managing director Ülo Uibo Chief accountant Linda Paade +372 742 8182 e-mail [email protected] +372 742 8948 e-mail: [email protected] +372 742 8133 e-mail: [email protected] +372 738 3032 e-mail: [email protected] 1.5. Directorial Board A regularly (once a week)-working deliberative assembly of directors and heads of structural units on councelling current problems of the Institute’s work. 1.6. Personnel Senior, assistant staff and graduate students of scientific projects Laser spectroscopy and applications of photosensitive materials Kikas Jaak, prof., proj. leader, PhD Aarik Jaan, head of group, MSc (0.5) Kuznetsov Anatoli, researcher, PhD Laisaar Arlentin, senior researcher, PhD Mauring Koit, senior researcher, PhD Mändar Hugo, senior researcher, PhD Organization and Personnel • 21 Palm Viktor, senior researcher, PhD Rebane Karl, senior researcher (0.5) prof. emer., DSc Lukner Argo, MSc student Renge Indrek, senior researcher, PhD Siimon Hele, researcher, PhD Sild Olev, senior researcher, PhD Sildos Ilmo, head of lab, PhD Suisalu Artur, senior researcher, PhD Kiisk Valter, PhD student, MSc Krasnenko Vera, PhD student, MSc Lange Sven, PhD student, MSc Pärs Martti, PhD student, MSc Marju Kleeman, MSc student Visk Urmo, MSc student Nanostructured materials Rosental Arnold, senior researcher, proj. leader, PhD Aarik Jaan, head of group, MSc (0.5) Adamson Peep, senior researcher, PhD Avarmaa Tea, researcher, PhD Jaaniso Raivo, senior researcher, PhD Kasikov Aarne, researcher, MSc Kink Ilmar, senior researcher, PhD Konsin Peet, senior researcher, (0.5) DSc Lõhmus Ants, head of lab, PhD Lõhmus Rünno, senior researcher, PhD Niilisk Ahti, senior researcher, PhD Saal Kristjan, researcher, MSc Sammelselg Väino, prof., PhD Sorkin Boris, researcher, PhD Uustare Teet, senior researcher, PhD Tätte Tanel, PhD student, MSc Tarre Aivar, PhD student, MSc Floren Aare, PhD student, MSc Kärkkänen Andrei, PhD student, MSc Kärkkänen Irina, PhD student, MSc Rammula Raul, PhD student, MSc Reedo Valter, PhD student, MSc Kodu Margus, MSc student Leinberg Martin, MSc student Lobjakas Madis, MSc student Paalo Madis, MSc student Pärna Rainer, MSc student Shulga Jevgeni, MSc student Timusk Martin, MSc student Vesi Urmas, MSc student 22 • Biannual Report 2004/2005 Vlassov Sergei, MSc student Aidla Aleks, engineer, PhD Asari Jelena, engineer Gerst Alar, engineer Kiisler Alma-Asta, engineer Lurich Robert, laboratory assistant Plaado Margo, laboratory assistant Matisen Leonard, engineer Ritslaid Peeter, engineer Biophysical elementary processes and their dynamics Freiberg Arvi, head of lab, prof., proj. leader, DSc Ellervee Aleksander, researcher, PhD Kangur Liina, researcher, MSc Leiger Kristjan, postdoc, PhD Rätsep Margus, senior researcher, PhD Timpmann Kõu, senior researcher, PhD Pettai Hugo, PhD student, MSc Radioactivity and dose in Estonian environment Realo Enn, senior researcher, proj. leader, PhD Haas Mati, senior researcher, PhD Kiisk Madis, postdoc, PhD Realo Küllike, head of lab, PhD Isakar Kadri, MSc student Aarik Lauri, MSc student Koch Rein, engineer, PhD Theory of the fundamental structure of the matter Hizhnyakov Vladimir, senior researcher, proj. leader, prof. emer., DSc Fedoseev Vladimir, senior researcher, PhD Järv Laur, researcher, PhD Kaasik Helle, postdoc, PhD Konsin Peet, senior researcher (0.5), DSc Kristoffel Nikolai, senior researcher, prof. emer., DSc Kuusk Piret, head of lab, DSc Liivat Hannes, PhD student, MSc Ots Ilmar, senior researcher, PhD Rebane Inna, senior researcher, PhD Rebane Karl, senior researcher (0.5), DSc Organization and Personnel • 23 Rubin Pavel, researcher, PhD Shelkan Aleksandr, researcher, Saal Margus, researcher, PhD PhD Sherman Aleksei, head of lab, Tehver Imbi, senior researcher, DSc DSc Sild Olev, senior researcher (0.5), Boltrushko Vadim, PhD student, PhD MSc Laser physics and laser-optical technologies Saari Peeter, head of lab, prof., proj. leader, DSc Jalviste Erko, researcher, PhD Kink Margarita, researcher, PhD Kink Rein, senior researcher, DSc Maksimov Juri, researcher, PhD Peet Viktor, senior researcher, PhD Reivelt Kaido, postdoc, PhD Selg Matti, senior researcher, PhD Stolovich Andres, senior researcher, PhD Treshchalov Aleksei, head of lab, PhD Shchemelev Sergei, PhD student, MSc Lissovski Aleksandr, PhD student, MSc Burak Sergei, MSc student Savustjan Grigori, MSc student Valtna Heli, MSc student Anijalg Agu, engineer Kilk Andrus, engineer Kippasto Avo, engineer Tsarenko Sergei, engineer Tsubin Vladimir, engineer Fundamental phenomena in wide-gap materials and their prospects of application Lushchik Aleksandr, head of lab, prof., proj. leader, DSc Babin Vladimir, researcher, PhD Dolgov Sergei, researcher, PhD Feldbach Eduard, senior researcher, PhD Kikas Arvo, head of lab, PhD Kirm Marco, research director, PhD Kisand Vambola, postdoc, PhD Kotlov Aleksei, researcher, PhD Kudryavtseva Irina, researcher, PhD 24 • Biannual Report 2004/2005 Kärner Tiit, senior researcher, PhD Käämbre Henn, assistant director, DSc Käämbre Tanel, postdoc, PhD Lushchik Cheslav, senior researcher, DSc Maaroos Aarne, senior researcher, PhD Nagirnyi Vitali, senior researcher, PhD Nõmmiste Ergo, director, PhD Ruus Rein, senior researcher, PhD Saar Agu, senior researcher, PhD Zazubovich Svetlana, senior researcher, DSc Vasil’chenko Evgeni, senior researcher, PhD Issahanyan Vigen, PhD student, MSc Kooser Kuno, PhD student, MSc Krasnikov Aleksei, PhD student, MSc Nakonechnyi Sergei, PhD student, MSc Galajev Semjon, MSc student Makhov Aleksei, MSc student Liblik Peeter, engineer Savikhin Feodor, engineer, PhD Supporting and maintenance staff All-institute personnel and assistant staff at grant/contract projects Tiismus Robert, leading computer specialist Koppel Hele-Mai, laboratory assistant Sikk Taimu, secretary Sildos Liivia, office assistant Soovik Hilja, engineer, PhD Vesman Elmar, engineerconsultant, PhD Book-keeping Paade Linda, chief accountant Saumaa Hannes, leading engineer Library Puusepp Tiia, head Luik Anne, lawyer Organization and Personnel • 25 Mechanics workshop Tammik Heini, head Ernits Inge, technician Hani Gustav, polisher Kivi Kalmer, locksmith Kuusk Andrei, miller Olev Karl, turner Parmas Ilmar, locksmith Rebase Valdek, welder Tarus Tõnu, miller Cryogenic service Tomberg Vello, head Vahi Jüri, engineer Management office Rand Anne, head manager Johanson Ants, locksmith Leppik Silvia, technician Mägimets Rein, electrician Otsa Vello, electrician Segar Enno, driver Toomsalu Jaan, electrician Truus Endel, technician Õunap Harri, locksmith Estonian Nanotechnology Competence Centre History In 2002 Estonian Government launched a Competence Centre Programme aiming at “To increase competitiveness of Estonian enterprises through strategic collaboration between industry and academia”. Institute of Physics was one of the leaders in the international consortium of public and private bodies that submitted a proposal to carry out a research programme in the field of nanotechnology and form a nanotechnology competence centre. The proposal scored second highest ranking during the international evaluation and was granted the requested funding by the Enterprise Estonia. The next step in the programme – the launch of the Centres – was, however, delayed considerable when one of the unsuccessful applicants decided to challenge the results in the court, the remarkable fact as being the first and so far fortunately the only attempt to carry over such a destructive and sadly common practice in business sector to (semi-)academic sphere. Despite everything, Estonian Nanotechnology Competence Centre (ENCC) was established in Dec., 2004 by companies Evikon MCI, K-TEK Int. (USA), Maico Metrics, MikroMasch Eesti, NexTech Supply, and University of Tartu. The main mission of the Centre is to provide scientific and technology oriented research in the field of nanotechnology. The research is funded by the partners of the Centre, Enterprise Estonia and European Union. Dr. E. Nõmmiste represents Institute of Physics in Centre’s Council and Dr. I. Kink in Estonian Nanotechnology Competence Centre • 27 the Board. Nearly 30 Institute’s researchers, mainly from the groups lead by Drs. R. Jaaniso, A. Rosental, and A. Lõhmus, are involved in collaborative research works. The research plan for 3 years was approved in Dec., 2004, and was partly revised in March, 2005 and November, 2005 due to changes in state aid regulations. The programme consists of three major research directions: Nanotechnological Gas Sensors, Nanodevices, and Nanometrology. Each orientation is divided into totally ten sub-projects. The Centre’s first year budget was 9 545 000 EEK (612 000 EUR), of which more than 90% were direct research costs. The team consisted of 20–30 scientists (PhD or MSc level), 10–15 laboratory assistants and 5 other staff members. The facilities included Partners’ infrastructures and other (rented) facilities if needed. The first results The Centre’s first scientific report was evaluated and fully approved by international experts. The Centre’s research efforts should deliver first applicable technologies in ca 3 years. Therefore, during the first year a lot of attention was focused on development of experimental facilities and initial tests of selected methods and materials. Thus, within the first direction, the research groups have developed/ modified experimental set-ups to measure electric responses of thin film gas sensor prototypes to varying gas-flow, temperature and illumination conditions. Also, many different thin films were characterized by Raman spectroscopy, RHEED, XRD methods to select the best candidates for sensors and to optimize their structure for the best performance. As an example of the research for the second and third research directions some results obtained by T. Tätte’s research group on development of oxide nano-tips will be presented below. The objectives of the project were: x Development of a method to obtain alkoxide based precursors, suitable for pulling nanometre level sharp oxide needles. Figure 1. Schematics of the nano-tips’ fabrication method. (T. Tätte) Figure 2. Sharpness of tin oxide nano-tips as a function of the fabrication (i.e. pulling) speed. The sharpest tip radius is approximately 15 nm. (T. Tätte, K. Saal) 28 • Biannual Report 2004/2005 x Development of experimental facilities and methods for pulling nano-tips from the viscous precursor. During the first year a “pulling machine” was developed, which operation principle is shown on Fig. 1. A lot of effort was placed to optimize the critical parameters of the precursor materials and the fabrication method. Among other results was discovered that the sharpness of the needles depends smoothly on the pulling characterristics as illustrated in Fig. 2. The tip radii of the needles were as small as 15–20 nm, which is suitable for many nanotechnological applications. Future plans The collaboration within the Centre’s framework is expected to deliver new technologies for making thin film based gas sensors, novel scanning probe tips and nanometrological calibration methods and standards during the coming few years. At the end of 2007 a new call for proposals will be announced and the Centre is optimistic to initiate several new research projects with old and new partners. Compiled by Ilmar Kink 2. GRANTS / CONTRACTS AND CO-OPERATION PARTNERS Foreign programs/grants/projects/contracts 1. Theoretical and experimental study of quantum dynamics and localization in nonlinear crystal lattices (2000–2002, 2003–2004), Estonia-USA NRC Twinning Program, Cornell University, USA (Prof. A. J. Sievers) and IP UT (Prof. V. Hizhnyakov) 2. Untersuchung dynamischer biomolekularer Eigenschaften durch 57 Fe-Kernstreu-experimente mittels Synchrotronstrahlung (2001– 2003, extended), Medical University of Luebeck, Germany (Prof. A. X. Trautwein) and IP UT (Dr. E. Realo) 3. Oxygen as a trace impurity in CaF2 (2002–2004), NATO Collaborative Linkage Grant PST.CLG.978807, IP UT (Prof. A. Lushchik) 4. Nanotribology network (2002–2006), European Science Foundation Programme, IP UT (Dr. A. Lõhmus) 5. CARIPLO Foundation fellowship (2003–2004), Landau Network, University of Milan, Italy (Prof. V. Hizhnyakov) 6. Medical Natural Sciences network (MedNatNet) (2003–2005), EU Education and Culture (Socrates) ERASMUS 3 (Prof. P. Mager, The Free University of Amsterdam), IP UT (Prof. A. Freiberg, co-ordinator) 7. Optical characterization of metal dioxide films (2003–2005), Research Grant II-03-019 at DESY, University of Hamburg; EU Foundation – Research Infrastructure Action (Dr. I. Sildos). 30 • Biannual Report 2004/2005 8. Synchrotron-based electron spectroscopy (2003–2006), Nordic Research Education Network for exploitation of synchrotron radiation, NORFA/NordForsk; University of Bergen (Norway), University of Uppsala (Sweden), University of Aalborg (Denmark) and IP UT (Estonia) (PI Prof. L. Saethre, Univ. of Bergen) 9. MolSimu (2004–2008), European Co-operation Programme COST-P13 (representative from Estonia – Dr. A. Lõhmus) 10. Doped metal-oxide nanomaterials for luminescence and gas sensing applications (2005), Research Grant at Angstrom Nano Centre, University of Uppsala; EU, Access to Research Infrastructure Action of the Improving Human Potential Programme (Dr. I. Sildos) 11. Time resolved single-molecule spectroscopy of terrylene in incommensurate biphenyl (2005), Research Grant IIc001119; EU, Programme LASERLAB-EUROPE (Dr. V. Palm) 12. Correlation between PDP firing voltage and luminescence properties of protective layer (2005), Co-operation Project with SAMSUNG SDI (PI Dr. E. Feldbach) 13. Development of new secondary electron emission materials and improvement of existing materials for PDPs using thin film technologies – pulsed laser, electron beam and atomic layer deposition (2005–2006), Co-operation Project with SAMSUNG SDI (PI Dr. M. Kirm) 14. Modelling of photosynthetic complexes under extreme conditions (2005–2006), Estonian-French Co-operation Programme on Research and Technology PARROT; CNRS/CEA, Saclay, Dr. M. Marchi and IP UT, Prof. A. Freiberg 15. Ce-doped aluminium perovskite and garnet single crystal and single crystalline film scintillators for high spatial resolution detectors (2005–2007), INTAS Grant No. 04-78-7083, NATO Science Programme (SfP) with collaboration partners from Czech Grants/Contracts and CooperationPartners • 31 Republic (Prague, Turnov), Italy (Milan) Ukraine (Lviv, Kiev) and Russia (Moscow); PI Dr. S. Zazubovich 16. Investigation of materials for radiation detection and lighting applications (2005–2007), Grant No. EAP.RIG.981411, NATO Programme “Security Through Science” (PI Dr. V. Babin). Co-operation partners Australia Austria Belgium Denmark Finland France Germany Australian Nuclear Science and Technology Organization ANSTO (Materials Division) University of Natural Resources and Applied Life Sciences Vienna (BOKU) (Institute of Meteorology) University of Liége, Institute of Physics (SUPRAS) Czech Republic Institute of Physics (Lab of Luminescence), Prague CRYTUR Ltd Co., Turnov Risoe National Laboratory Aalborg University (Institute of Physics) University of Helsinki (Lab of Inorganic Chemistry) Technical University of Helsinki (Lab of Inorganic and Analytic Chemistry) University of Jyväskylä (Dept of Chemistry) University of Oulu (Dept of Physical Sciences) University of Turku (Dept of Applied Physics) Tampere University of Technology (Surface Science Lab) Helsinki Institute for Physics (HIP) CNRS/ CEA, Saclay Laser-Matter Interaction Centre International Agency for Research on Cancer (Radiation Group) CNRS Bordeaux University of Stuttgart (Institute of Theoretical Physics) 32 • Biannual Report 2004/2005 Hungary Italy University of Hamburg (Institute of Experimental Physics, HASYLAB at DESY) University of Regensburg (Institute of Applied Physics) University of Jena (Institute of Theoretical Physics) University of Erlangen-Nürnberg University of Würzburg Lübeck University (Institute of Physics) Technical University of Chemnitz (Institute of Physics) Max-Planck-Institute of Bioorganic Chemistry, Mühlheim Max-Planck-Institute for Solid State Research, Stuttgart Humboldt University, Berlin Kiel University (Institute of Physical Chemistry) Friedrich-Schiller-Universität, Jena Gesellschaft für Schwerionenforschung (GSI), Darmstadt Great Britain University of Sheffield (Robert Hill Institute of Photosynthesis, Krebs Institute of Biomolecular Investigations) University of Glasgow (Dept. of Biochemistry and Molecular Biology) University College, London University of Oxford Eötvös Lorand University (Dept of Organic Chemistry) Institute for Solid State Physics and Optics, Hungarian Acad. Sci., Budapest University of Szeged (Dept of Physics) Institute of Applied Physics, Florence (Lab of Laser Spectroscopy) University of Milan-Bicocca (Dept of Material Science) Institute of Photonics and Nanotechnology, Trento University of Messina Grants/Contracts and CooperationPartners • 33 Japan Japan Atomic Energy Research Institute University of Hokkaido (RIES) Kazakhstan University of Aktyubinsk Almaty State University Latvia University of Latvia (Institute of Solid State Physics), Riga Institute of Solid State Physics, Riga Lithuania Institute of Physics, Vilnius Vilnius University (Dept of Theoretical Physics) Mexico University of Sonora The Netherlands University of Groningen (Materials Science Centre) University of Leiden Norway University of Bergen (Dept of Chemistry) Russia Lebedev Physical Institute, Moscow Institute of General Physics, Moscow Kirenski Physical Institute, Krasnoyarsk Ioffe Physico-Technical Institute, St.Petersburg University of St.Petersburg Herzen State Pedagogical University, St.Petersburg Ural State Technical University Spain University of Valladolid (Inst. of Electronics and Telecommunication) Universidad Autonoma de Madrid Sweden Lund University (Dept of Physics; Lab of Solid State Physics; MAX-Lab; Dept of Chemical Physics) Lund Laser Centre (Division of Atomic Physics) University of Uppsala (Dept of Physics; Ångström Lab) Chalmers University of Technology (Dept of Applied Physics), Göteborg Royal Institute of Technology (Dept of Theoretical Chemistry), Stockholm 34 • Biannual Report 2004/2005 Ukraine USA Institute for Scintillation Materials (ISMA), Kharkov Lviv University (Lab of Luminescence) Institute for Problems of Materials Science of the National Acad. Sci. of Ukraine, Kiev Cornell University (Dept of Atomic and Solid State Physics), New York Montana State University (Dept of Physics) University of Hawaii (School of Ocean and Earth Science and Technology) 3. RESEARCH HIGHLIGHTS Difference fluorescence line narrowing – an effective selective spectroscopy tool for studies of complex molecular systems Arvi Freiberg and Margus Rätsep Great progress has been made in optical spectroscopy of impurity centers in solids since the development more than 30 years ago of two basic spectrally selective techniques: fluorescence line narrowing (FLN) [1] and spectral hole burning (HB) [2]. Clearly, advent of lasers was the main prerequisite of this advance. Spectral HB involves a quasi-monochromatic laser light to selectively bleach a narrow isochromat of chromophores or aggregates of chromophores within an inhomogeneously broadened absorption band. Hole burning occurs when resonance with electronic transitions of the chromophore is destroyed by photo-induced changes of the chromophores electronic states, by structural rearrangements of the host environment, or both. The first mechanism is commonly referred to as photochemical HB, while the second, as non-photochemical HB. It is worth noticing that non-photochemical HB is typical for chromophores in amorphous matrices such as inorganic and organic glasses, polymers, and proteins. The hole-burned spectrum is obtained as the difference between the absorption spectra taken before and after the bleaching process. It was soon realized that although much more clear-cut than the bands measured by common absorption spectroscopy, the shape of the HB spectrum does generally 36 • Biannual Report 2004/2005 not directly represent the homogeneous absorption spectrum, that is, the selectivity of HB is limited. In the case of a single matrixembedded chromophore at low temperatures the homogeneously broadened spectrum typically consists of series of narrow zerophonon lines corresponding to the purely electronic and electronvibrational (vibronic) absorption transitions between the two electronic states of the chromophore. Each zero-phonon line is accompanied from the high-energy side by a broad sideband due to coupling of the electronic transition to the matrix phonons (Fig. 1). As a result of this, even a monochromatic excitation within the zero-phonon line will not ensure complete spectral selection. A comparably fraction of molecules will simultaneously be excited via their phonon sidebands leading to a complex HB line shape. In the case of weak vibronic coupling the spectral holes can be burned only in the inhomogneously broadened purely electronic absorption region. The HB spectrum then consists of two broad features called real- and pseudophonon sideband (PSB) holes, respectively, at energies higher and lower relative to the narrow zero-phonon hole (ZPH) at the burn laser frequency. As the names tell, the real-PSB represents phonon transitions that are excited resonantly via zero-phonon lines, while pseudo-PSB, those that are excited non-resonantly through their phonon sidebands. There is also a weaker multi-phonon (multi-PSB) contribution distributed on both sides of ZPH. It represents phonon sidebands of zero-phonon lines associated with the pseudo-PSB holes. A spectral distribution of ZPH depths measured at constant nonsaturating burn fluence results in the so-called ZPH action spectrum or site distribution function (SDF in Fig. 1), which is a measure of static inhomogeneous spectral broadening. Similarly to HB in absorption, FLN spectroscopy employs monochromatic laser light to selectively excite emission from chromophores within their inhomogeneously broadened ensemble. The resulting line-narrowed fluorescence spectrum can again be related to its underlying homogeneous spectrum. Spectral HB and FLN are thus pre-burn post-burn SDF ' FLN SDF real-PSB SDF pseudo-PSB multi-PSB frequency pseudo-PSB multi-PSB SDF real-PSB 'A Figure 1. Model difference fluorescence line narrowing ('FLN) and hole burning ('A) spectra exposing their component spectra. Upper part of the figure shows inhomogneously broadened site distribution functions (SDF) before and after persistent spectral hole burning. A contribution of photoproduct spectra is left out for clarity. See text for further details. Research Highlights • 37 complementary line-narrowing techniques, in the lowest approximations of theoretical models providing equivalent information about photoactive material centers. In practice, however, there are differences related how the zero-phonon line and various phonon sideband components are represented in the experimental spectra. The shape of the homogneously-broadened spectrum of the twolevel impurity center in the low-temperature matrix is determined by the density of phonon states of the matrix, weighted by the electron– phonon coupling strength. The latter can be characterized by the total dimensionless Huang-Rhys factor, S, which determines the mean number of phonons absorbed or emitted upon the electronic transition in the impurity center. The integrated intensity of the zerophonon line component divided by the intensity of the entire (zerophonon plus real-PSB) spectral profile is equal to exp(–2S). Therefore, the HB spectrum where the real- and pseudo-PSB components lie on opposite sides of the ZPH seem to allow a rather straightforward analysis of the low-frequency phonon contributions directly from the experiment. Yet, the high-energy side of the experimental HB spectrum is normally distorted by the absorption of HB products, which in the case of non-photochemical HB tend to randomly redistribute within the whole span of SDF. Also, as can be seen from Fig. 1, the limited width of SDF suppresses the highfrequency phonon part of the pseudo-PSB component spectrum. Ignoring these aspects may lead to serious underestimation of the actual Huang–Rhys factor. On the other hand, in FLN the real-, pseudo-, and multi-PSB parts, all lie towards lower energy from the zero phonon line. Counting of pseudo-PSB and multi-PSB parts present in experimental spectra now results in overestimation of the Huang–Rhys factor. However, far more serious obstacle in this case is the excitation laser scattering (Rayleigh scattering) artifact that usually totally obscures the zero-phonon line. These shortcomings of FLN and HB techniques are well recognized. Various solutions to handle the problem, typically exploiting 38 • Biannual Report 2004/2005 optical saturation of zero-phonon transitions due to vastly different absorption cross-sections of the zero-phonon line and of its phonon sideband, have been proposed (see reviews by Rein Avarmaa and Jaak Kikas in [3], and references therein). Among the most promising techniques, dubbed here as difference fluorescence line narrowing ('FLN) spectroscopy, is the one that uses persistent spectral HB to gain selectivity. As the difference between the pre-burn and post-burn absorption spectra yields the persistent HB spectrum, that between the emission spectra produces the 'FLN spectrum. The 'FLN spectrum thus shows the contribution of the emission that has been lost due to hole burning, that is, it corresponds to the sites or states that were burnt out during irradiation. The utility of this technique has previously been demonstrated on vibronic transitions of some organic impurity centers in glassy matrices [3, 4]. We have recently extended this method on delocalized exciton spectra in photosynthetic antenna pigment-protein complexes [5–7]. Shown in Fig. 2 are a series of common FLN spectra (curves a to e) measured at different excitation fluences and the 'FLN spectrum ((a-e)/2) of excitons in FMO antenna bacteriochlorophyll-protein complexexes isolated from the green photosynthetic bacterium Chlorobium tepidum. The total spectrum on inset demonstrates one of the greatest advantages of 'FLN with respect to the FLN spectrum: the zero phonon line in difference spectrum is virtually free from excitation laser scattering artifact. This allows a clear-cut determination of the above-described homogeneous spectral parameters from purely electronic emission transitions for the first time. A decisive factor in this achievement (apart from successful efforts to minimize scattered laser light by controlling the quality of the sample, special design of the cuvette holder, spatial filtering of the excitation beam etc.) was the usage of modern technology based on CCD camera that by simultaneous recording of the whole spectrum maximizes the signal-to-noise ratio. ' FLN 827.1 nm a FLN/ ' FLN b c d 826 830 834 e (a-e)/2 826 830 834 838 842 Wavelength (nm) Figure 2. Fluorescence line-narrowing spectra of the FMO complex at 4.2 K. The five FLN spectra from top to bottom correspond to excitation light fluences at OE=OB=827.1 nm of 1.6 (virtually no hole burning), 4.8, 8.0, 28 and 126 mJ/cm2. The lowest curve shows a difference between the initial and the 126 mJ/cm2 post-burn fluorescence spectra, the 'FLN spectrum. The spectra are magnified in order to bring out the sideband details. An overview of the 'FLN spectrum is shown on inset. Figure 3. Phonon sidebands of 'FLN spectra of bacteriochlorophyll a molecules in different surroundings. See text for details. Research Highlights • 39 Yet another advantage of the 'FLN technique can also be noticed on Fig. 2. There is a shoulder near 837 nm in FLN spectra that can be due either to low energy intramolecular modes of the photoactive bacteriochlorophyll a pigments or by non-resonantly excited fluorescence of a residual reaction center core complex, not subject to bleaching at OE=827.1 nm. The 'FLN spectrum indicated by (a-e)/2 clearly favors the second choice, at the same time revealing the actual contribution of intramolecular modes around 839–841 nm. This increased selectivity is an immense gain when complex systems like photosynthetic antennas or polymers are studied. The phonon sidebands of line-narrowed spectra are considered to reflect local dynamics of the matrix directly surrounding the probe chromophores. By virtue of the above properties of 'FLN spectra, this technique can be very useful for such dynamics studies. Demonstrated in Fig. 3 are phonon sidebands of 'FLN spectra of bacteriochlorophyll a molecules in several glassy matrices of protein and polymeric origin at 4.2 K. We notice that the probe molecules are well isolated from each other in all samples, except that in the LH2 antenna complex (represented with blue curve in Fig. 3) where the pigments are electronically strongly coupled and excitons are formed upon excitation by light. As can be seen from Fig. 3, the isolated molecules all show similar spectra with a distinct maximum that is red-shifted by ~20 cm–1 relative to the zero phonon line, despite evident differences in the local structure of the surroundings of probe molecules: a protein matrix of predominantly E-sheet conformation in FMO complexes (green curve, the same as curve (a-e)/2 in Fig. 2), a protein matrix of D-helix conformation in LH2 complexes (blue), and a polymer (polyvinylbutyral) glass (black). This maximum, the so-called boson peak, is characteristic to phonons in amorphous solids and represents an increased density of phonon states over that of classical Debye density in perfect crystals. There, however, has so far been no consensus about the physical origin of the boson peak. The shape of 40 • Biannual Report 2004/2005 the sideband of the 'FLN spectrum of LH2 antenna complexes (blue curve) appears even more challenging. According to [6–8], this spectrum is due to large-radius excitonic polarons whose wavefunction is localized on a number (5–8, depending on the system) bacteriochlorophyll a molecules. A reduced interaction with intramolecular vibrations around 200 and 350 cm–1 is a clear evidence of delocalized nature of the exciton polaron wavefunction. Strong coupling of the exciton to the pair-wise inter-pigment vibrational modes has been proposed as probable cause of the sideband transformations observed (relative to the spectra for isolated pigments) [7]. There in LH2 complexes is also a small amount of dysfunctional bacteriochlorophyll a molecules that are unable for fast intermolecular energy transfer (drawn in red on Fig. 3). Their spectra are almost indistinguishable from the ones in polymer matrix. This once again implies that the molecular probes (at least such big as bacteriochlopylls) in amorphous matrices actually sense not the direct surroundings but a much more extended space around them. REFERENCES 1. A. Szabo, Phys. Rev. Lett. 25, 924–926 (1970). 2. A. A. Gorokhovskii, R. K. Kaarli, L. A. Rebane, JETP Lett. 20, 474-476 (1974); B. M. Kharlamov, R. I. Personov, L. A. Bykovskaya, Opt. Commun. 12, 191–193 (1974). 3. O. Sild, K. Haller (Eds.) Zero-Phonon Lines and Spectral Hole Burning in Spectroscopy and Photochemistry, Springer-Verlag, Berlin, Heidelberg, 1988. 4. J. Fünfschilling, D. Glatz, I. Zchokke-Gränacher, J. Luminescence, 36, 85–92 (1986). 5. M. Rätsep and A. Freiberg, Chem. Phys. Lett. 377, 371–376 (2003). 6. K. Timpmann, M. Rätsep, C.N. Hunter and A. Freiberg, J. Phys. Chem. B 108, 10581–10588 (2004). 7. M. Rätsep, C.N. Hunter, J. D. Olsen, A. Freiberg, Photsynth. Res. 86, 37–48 (2005). 8. G. Trinkunas, A. Freiberg, J. Luminescence 112, 420–423 (2005) Research Highlights • 41 Probing anomalous ZZJ and ZJJ couplings in e+e– o ZJ with polarized initial beams Ilmar Ots and Hannes Liivat Our present theory of the fundamental interactions of the elementary particles – the Standard Model (SM) – is phenomenologically successful. At present the SM is in consistence with all acceleratorbased experiments. However, several fundamental questions remain unanswered by the SM. Obviously, as a theory in its present form, the SM is not satisfactory and it is widely expected that there exists more fundamental New Physics (NP) beyond the SM, with new characteristic high mass scale. The most straightforward method for searching NP would be the production of NP particles. Such a scenario for visualizing NP experimentally is beyond the reach of current accelerators and can be carried out only at future colliders. More indirect ways to investigate NP are based on observation of small departures from the SM predictions in processes, where the external particles are ordinary SM ones, and NP effects can arise only from non-standard interactions. It is believed that one of possible such sources of NP may be the existence of anomalous gauge boson self-couplings. Motivated by this possibility such couplings have been theoretically extensively investigated and experimentally tested. Though to date no evidence of anomalous gauge boson self-couplings has been established, the bounds obtained at the CERN e+e- collider and at the Fermilab Tevatron are comparatively weak [1]. It is also clear that the current accelerators cannot provide sensitivities which would be considerably better than the ones already achieved. However, the study of gauge boson self-interactions is an important item in the physics of the planned next generation colliders. As soon as the proposed high energy colliders start running, a dramatic improvement on the sensitivity of the experiments to nonstandard couplings is expected. 42 • Biannual Report 2004/2005 Among gauge boson self-couplings the most sensitive probes of NP are provided by the couplings of three neutral gauge bosons. Among processes to which such couplings could contribute are the neutral gauge boson productions in e+e- annihilation. The processes (e+e- o ZJ, ZZ, JJ) are particularly interesting and promising in various aspects. The final gauge bosons are easy to detect experimentally, while the theoretical structure of the processes provides clean and unambiguous test of the SM electroweak interactions. From the other side, the SM predicts here no tree level (the lowest order) selfcouplings and the higher order loop level corrections are vanishingly small. Therefore, the precision measurements of these processes can without ambiguities be compared with the SM predictions and any deviation from these can be considered as contributions from anomalous couplings [2]. A future e+e- International Linear Collider (ILC), operating in the wide energy range up to about 1 TeV and designed with high luminosity, provides an excellent discovery potential. An additional advantage of the ILC is the possibility to have at it both initial beams longitudinally polarized. Since by using spin rotators the longitudinal polarization (LP) can be converted into the transverse polarization (TP), another powerful tool of the ILC will be available – the use alongside with longitudinally polarized beams also transversely polarized ones. Due to these possibilities, the roles of polarizations, especially the role of TP in the process with the possible anomalous parts of couplings have attracted noteworthy attention in recent years. A considerable part of these investigations is constituted by the ones considering the LP and TP effects in the aforementioned processes, particularly in e+e- o ZJ [3]. However, the studies connected with the roles of LP and TP in searching anomalous couplings are yet far from being exhaustive. The aim of our investigations [4,5] was to calculate and analyse the possible corrections of anomalous ZZJ and ZJJ couplings to the spin orientation of the Z boson in the process e+e- o ZJ with longi- Research Highlights • 43 tudinally and transversely polarized initial beams and with accentuation of the roles of LP and TP in disentangling the contributions from different couplings – SM, ZZJ and ZJJ. In most papers the spin-related studies have been carried out by employing the helicity basis. The method of summing the Feynman diagram with definite helicities of initial and final particles has proved to be a powerful tool for describing the spin polarization phenomena. However, quite often one can reach the desired results comparatively easily by using other methods. The method we followed is the one that uses in the squared amplitude of the process the relativistic spin1 density matrix, obtained by applying the Lorentz boost to the nonrelativistic one. In this case the squared amplitude is proportional to the probability that the spin orientation of the Z boson is described by the density matrix determined by the given rest frame polarization vector and alignment tensor, and it is not a difficult task to deduce from the squared amplitude the expressions for the actual spin polarization vector ti and the alignment tensor tij of the Z boson. A detailed description of the method can be found in [6]. By exploiting the method described, we found the analytical expressions for the S (the part of the squared amplitude, independent of the Z boson spin orientation parameters) and for the polarization vector ti and alignment tensor tij of the final Z boson from e+e- o ZJ with LP and TP initial beams and in the presence of anomalous ZZJ and ZJJ couplings. In our calculations we limited ourselves to the lowest order approximation, linear to the anomalous couplings. In this approximation the process is described by two SM Feynman diagrams and by two diagrams with the anomalous vertices and for anomalous couplings effects only the interference of the SM and anomalous couplings amplitudes are taken into account. General expressions for anomalous ZZJ and ZJJ vertices have been given in [7]. In the CP-conserving case (which we presumed) both of these couplings are parametrized in terms of two form-factors, which are restricted by unitarity conditions at high-energy: h3Z, h4Z for ZZJ and 44 • Biannual Report 2004/2005 h3J, h4J for ZJJ couplings. The evaluation of needed expressions is quite routine, based on using the Lorentz boosts and the trace techniques for the Dirac spinors with the longitudinal and transverse components of the electron and positron polarization vectors. In the calculations, the electron mass has been taken negligible as compared to the energy scale of the process. The final expressions have been given in the centre-of-mass system, which coincides with laboratory frame in actual experiments. By the analytical expressions for the polarization vector and alignment tensor the spin orientation of the Z boson from e+e- o ZJ with LP and TP beams and in the presence of possible anomalous ZZJ and ZJJ couplings is fully described. The orientation of the Z boson is transferred to the angular distribution of its charged leptons decay products. As a consequence, one can put limits to the anomalous couplings (to the values of form-factors hiZ and hiJ) by probing the Z boson spin orientation through the measuring of the shape of the Z boson lepton decay spectrum. We do not give here the calculated analytical expressions for the LP- and TP-dependent contributions to the Z boson spin orientation. These expressions, especially the ones describing TP-dependent part of the Z boson alignment tensors, are not very simple. However, these expressions have a structure from which their features can easily be learned. In what follows we give the general features of the LP- and TP-dependent contributions from SM, ZZJ and ZJJ which can be deduced from the expressions. 1) All contributions from the anomalous couplings vanish at the threshold of the process. 2) All anomalous contributions vanish when the Z boson is emitted in or against the direction of the initial electron. 3) Unlikely to LP contributions, the TP contributions are different from zero only when both the electron and the positron are simultaneously transversely polarized. Research Highlights • 45 4) Differently from the LP-dependent contributions, the different couplings (SM, ZZJ, ZJJ) do not give TP-dependent contributions to all quantities calculated, i.e. to S, ti and tij . Only the anomalous ZJJ couplings contribute the TP-de-pendent part to all of these quantities. The SM does not contribute to ti and, on contrary, the ZZJ couplings contribute only to ti . This feature could be very helpful for disentangling the contributions from different (SM, ZZJ, ZJJ) couplings. 5) In absence of TP, the contributions to the process depend on the coupling constants and on the beam LP parameters only through the common factors in front of various types of couplings. Due to this, LP does not enable any measurement of the parts of couplings which are inaccessible with unpolarized beams. By changing the values of the LP parameters one can substantially enhance the sensitivities to one or other part of couplings which, however, at least in principle, are measurable also in the case of unpolarized beams. 6) Contrary to the LP contributions, the TP contributions are not factorized in such way and as a consequence, TP can enable the measurements which are not accessible with LP or unpolarized beams. 7) TP provide the theory with extra directions. Thanks to the TP vectors, the Z boson polarization vector ti obtains additional, generally out-of-reaction-plain components and new alignment axes are added to the spin orientation tensor tij. Some of these features (feature 1 and feature 3) have been noticed earlier. However, by using the fully analytical expressions for the contributions, all their properties can be more clearly and explicitly demonstrated. To get a feeling about possibilities for using the properties of the LP and TP contributions for testing the SM and NP, we proceed with an example. Since the SM generates no TP-dependent terms in ti 46 • Biannual Report 2004/2005 (feature 4), any such term has to be from the anomalous couplings contributions. Due to the ZZJ and ZJJ TP-dependent contributions to the Z boson polarization vector, the latter obtains additional part (feature 7), which generally lies not on the reaction plain. As a conesquence, the whole Z boson polarization vector (unlikely to the ti from LP or from unpolarized contributions) is outside the reaction plain. Hence, the existence of the angle between the Z boson polarization vector and the reaction plain indicates the anomalous self-couplings contributions from the transversely polarized initial beams. Let us for concreteness and simplicity restrict ourselves to a very special case. Firstly, we take only one of the anomalous couplings (h3J) different from zero with the value h3J=0.001 at the centre-of-mass energy 500 GeV. Secondly, for choosing the degrees of polarization we depart from the values of the longitudinal polarizations foreseen in the base line design of the ILC (Le-=0.8, Le+=0.6) and assume a 100% efficiency of spin rotators, i.e. we take the values of the transverse polarizations to be 7e-=0.8 and 7e+=0.6. Thirdly, we take the TP vectors of e- and e+ to be perpendicular to each other. Then, in the case when the Z boson is emitted in the directions perpendicular to the electron momentum, D=2o, which would be certainly within the sensitivity reach of the ILC. In conclusion, our papers provide a set of expressions which can be used to constrain anomalous couplings between three neutral gauge bosons. Our investigations were partly supported by ESF grants Nos. 4510 and 6216. REFERENCES 1. L3 Collaboration, M. Acciarri, et. al., Phys. Lett. B 489 (2000), 55; B. Abreu, et. al., Phys. Lett. B 497 (2001), 199; D0 Collaboration, S. Abachi, et. al., Phys. Rev. D 56 (1997), 6742; B. Abbot, et. al., Phys. Rev. D 57 (1998), R3817. Research Highlights • 47 2. G. J. Gounaris, J. Layssac, F. M. Renard, Phys. Rev. D 67 (2003), 013012. 3. G. Moortgat-Pick, et. al., arXiv:hep-ph/0507011; B. Ananthanarayan, S. D. Rindani, Phys. Lett. B 606 (2005) 107; B. Ananthanarayan, S. D. Rindani, JHEP 10 (2005) 077. 4. I. Ots, H. Uibo, H. Liivat, R.-K. Loide, R. Saar, Nucl. Phys. B 702 (2004), 346. 5. I. Ots, H. Uibo, H. Liivat, R.-K. Loide, R. Saar, Possible anomalous ZZJ and ZJJ couplings and Z boson spin orientation in e+e- o ZJ: the role of transverse Polarization, Nucl. Phys. B (accepted). 6. I. Ots, H. Uibo, H. Liivat, R.-K. Loide, R. Saar, Nucl. Phys. B 588 (2000), 90. 7. K. Hagiwara, R. D. Peccei, D. Zeppenfeld, K. Hikasa, Nucl Phys. B 282 (1987), 253. Cuprate superconductivity characteristics on the doping scale. A simple model Nikolai Kristoffel The present article reflects in some extent the elaboration of a simple model by the author and Pavel Rubin which describes qualitatively the behaviour of cuprate superconducting characteristics on the whole doping scale. This model is based on the electron spectrum of a charge transfer insulator essentially modified and evolving with the hole doping. Cuprates belong to strongly correlated compounds and the doping separates in them the defect subsystem bearing the introduced carriers from the itinerant background. Interaction of these electronic subsystems is considered as the decisive channel for the superconductivity of cuprates in the model under consideration. Nearly 20 years have been passed from the Müller and Bednorz discovery of the high temperature superconductivity in La2–xMxCuO4 48 • Biannual Report 2004/2005 (M=Sr, Ba). A huge experimental, theoretical and technical research on cuprates and relative compounds has been started and continues. A number of highly valuable results and conclusions have been obtained. However, the central problem of the nature of cuprate superconductivity remains elusive. Various refined and deepgoing approaches have not given decisive inferences. For this reason the author has proposed another way. A very simple, partly postulative, but plausible model of cuprate superconducting functionality has been developed. It uses only gross features known from numerous experimental and theoretical works. The outcome of the model is expected to serve a phenomenological framework for embedding more throughout theories on enlightened physical background. Our model reflects the two-component scenario [1] of cuprate superconductivity. Its essence consists in that a “defect-polaronic” subsystem bearing doped holes is functioning besides the itinerant valence band electrons. The model has been started in [2,3] and at present [4–6] the defect subsystem is described by two subbands (D) (“hot”) and (E) (“cold”) to distinguish the different functioning of the S S (S,0) and ( , )-type regions of the momentum space. These bands 2 2 are supposed to be gapped from the mainly oxygen itinerant band (J) until the progressive doping brings them into overlap. This overlap dynamics of normal state gaps opens a novel source of critical doping concentrations on the doping phase diagram. At the same time such a reorganisation of the spectrum opens a novel possible pairing channel by the interband pair transfer between the defect and itinerant states. The interband mechanism of superconductivity has been known for a long time. High transition temperatures can be reached on this way out of exotic conditions. Intersection (interference) of various bands at the Fermi energy is the prerequisite for its functionality [7,8]. In cuprates the doping procedure seems to prepare such conditions in the actual doping region. The interest for the two-band superconductivity has been Research Highlights • 49 especially grown with the recent discovery of a new high-Tc superconductor MgB2. In magnesium diboride which is a two-gap system the interband pairing channel plays a remarkable role [9]. The twoband superconductivity model has been investigated in the Institute of Physics extensively [7]. The theoretical description of the model under consideration where the pairs built up from the particles of the same band are scattered between the defect and the itinerant bands can be performed in a standardized manner [2,3,7]. The central term in the Hamiltonian describing the multiband pairing is expressed by W ¦ ¦¦ aV VV ' & & & , ' k ,k ' q & a & & a & & a & k n V k q p V ' k ' q p V ' k 'n with the creation operators of electrons for fixed spins aV n in the & bandsV; q is the pair momentum. The interband coupling constant W=V+U contains an electron-phonon (V) and Coulombic contribution U. It is supposed that W>0. The interband scheme has also the advantage that the pairing can be reached by the repulsive interaction. There are the following qualitatively different arrangements of the band components and of the chemical potential (P). At the very underdoping P is connected with the “cold” defect band bottom and the normal state spectrum is fully gapped. At the doped hole concentration p E theE–Joverlap starts andPenters the itinerant band. The optimal doping region corresponds to the overlap of all the band components being intersected by the chemical potential. At extended overdopingPfalls out from theE-band and the conditions for the interband pairing mechanism deteriorate. Correspondingly the Tc vs doping curve, as also the supercarrier density ns and the superconducting gaps 'D ,J are bell-like, see Fig.1 and Fig.3. The characteristic ratios 2'V / k BT c for the superconducting gaps violate markedly 50 • Biannual Report 2004/2005 the Bardeen-Cooper-Schriffer universality. There are doping regions where these ratios grow, while the transition temperature diminishes, cf. [10,11]. In the two-band approaches such observed “anomalies” are usual. Progressive doping enhances the total concentration of the charge carriers. On this background, however, the superfluid density diminishes at overdoping. This problem [12] becomes naturally solved by suppression of the interband pairing in this region. It must be also noted that the bare normal state gaps does not manifest in opening of fermionic gaps in the supefluid density because of the interband nature of the pairing. The excitation spectrum near the Fermi energy is determined by the minimal energies of the quasiparticles ( EV ). In our model with the doping-variable spectrum the nature of these energies changes (H V P ) 2 '2V can be minimized by with doping. Namely, if EV H V P with the chemical potential in the corresponding band, the low-energy spectrum is determined by the superconducting gap ' V . In the opposite case the minimal value of EV represents in a natural way the appearance of a pseudogap ' V (ps) which survives as a normal state gap. As the result, the manifestation of the four actual gaps of the model in the “hot” channel ' V , J (ps) and ' D , J depend on the level of doping. At expressed underdoping two pseudogaps can be observable in general. If the cold defect subsystem is born as nongapped, there remains only one (the larger) pseudogap ' D (ps). The smaller pseudogap, if present, transforms at p E to the larger (itinerant) superconducting gap, cf. [13]. The large pseudogap (spectral hump) ' D (ps) extends until it is quenched in a slightly overdoped region and crosses ' J , cf. [14,15]. At overdoping the spectrum is determined by both superconducting gaps. Spectrally the smaller superconducting gap (also in presence of a pseudogap) manifests itself in an additional density on the wings of the spectral hole due to the larger gap ( ' J or ' D (ps)). Research Highlights • 51 According to our model the pseudogap can be considered as a precursor of the superconducting gap on the doping scale, but not on the energy scale. Experimentally one sees [10,11] in the normal state the gap features at the phase diagram points, where in the superconducting state one observes the superconducting gap. This corresponds exactly to the result of our model. The direct metallization of the cold subsystem is reached at p E . The hot defect subsystem metallizes near the optimal doping. A common mixed Fermi liquid is there built up. One expects a normal state insulator to metal transition at this composition in agreement with the observations [16]. It is also known that in infrared the manifestation of the defect subsystem becomes here suppressed in favour of a free carrier Drude peak [17]. In this manner the present model reproduces qualitatively the observed behaviour of cuprate energetic characteristics on the doping scale and relations between various gaps [10]. The presence of two pseudogaps at underdoping has been observed recently for some systems [12]. A plausible parameter set has been used to illustrate these results in Fig.1. For a “typical” cuprate the Tc | max | has been adjusted to p=0.16. For the calculation of various thermodynamic characteristics a Ginzburg-Landau type expansion of the free energy of the model in & 4-th order of the two order parameters, (T–Tc) and q has been performed in collaboration with Teet Örd. The mixed nature of the order parameters of the two-component superconductor leads to the appearance of the “soft” and “rigid” components of superfluid wave functions governed by different coherence scales [18]. The soft coherence length behaves critically at Tc and the corresponding order parameter component determines both superconducting gaps. The other rigid coherence length behaves noncritically and describes a periodic spatial coherence wave. 52 • Biannual Report 2004/2005 0.04 2 1 eV 0.03 3 0.02 4 0.01 5 0.00 0.00 0.05 0.10 0.15 0.20 0.25 0.30 p Figure 1. Doping dependence of the gaps and Tc (5). 1; 2 – the small and the large pseudogap. 3; 4 – the superconducting gaps of the defect and the itinerant subsystem. The superconductivity playground CuO2 in-plane coherence length is shown in Fig.2 [19]. This “valley profile” nonmonotonic curve agrees with the recent experimental result [20] where ] has been measured on the whole doping scale. This result may be qualified as being expected – weakly coupled pairs have larger dimensions. The second c-axis critical field H c 2 (0) shows a well expressed maximum, as also the condensation energy and the superfluid density show (Fig. 3). In the present model the strength of the pairing and the phase coherence develop and vanish simultaneously in accordance with the conclusions in recent experimental investigations [12,13,21,22]. Research Highlights • 53 [/[0.15 3 a 2 1 [(A) 0 300 b 200 100 0 0.00 0.05 0.10 0.15 0.20 0.25 0.30 p Figure 2. The CuO2 plane coherence length on the doping scale (a) and the experimental result of [20] (b). ns 0.040 16 0.035 14 0.030 12 0.025 10 0.020 8 0.015 6 0.010 4 0.005 2 0.000 0.00 0.05 0.10 0.15 0.20 0.25 mab/m0 0 0.30 p Figure 3. The supercarrier effective mass theoretical dependence (dashed line) on doping and the supercarrier density (solid line). 54 • Biannual Report 2004/2005 The paired carrier effective mass ( xm0 with m 0 of the free electron mass) doping dependence [23], not been obtained earlier to the author best knowledge, is given in Fig. 3. The overall m ab reduction with doping reproduces the well-known trend to restore the Fermiliquid behaviour of the superconducting carriers. The magnetic penetration depth ( O )is determined by the ratio pn s / x . According to our calculations the strong nonmonotonic dependence of the supercarrier density overwhelms here. This leads to a O 2 curve with an expressed maximum in agreement with numerous experimental findings [12, 21, 22]. The transition temperature isotope effect in cuprates is very specific: its characteristic exponent D is small where the transition temperature is remarkable [24] and vice versa. The explanation of this trend is given also by the interband nature of the pairing [7,18]. A relatively small contribution (V/W) of the interband electron-phonon pairing, which is inverse proportional to the active vibration mass can serve remarkable D -s for small Tc -s. Roughly, Tc in the present model is large where distinct exponential coefficients minimize the Tc (electronic) scale quenching. On the contrary, D is determined by these terms, i.e. it is larger for dopings with relatively small Tc -s. The two-component scenario explains also the presence of a critical and noncritical relaxation channel in cuprates [25]. In this manner the present model describes qualitatively the behaviour of various cuprate superconductivity characteristics on the whole doping scale in an unified approach. The simplicity of the model allows wide freedom to fill it in with precised assumptions, improvements and quantitative content. We believe that cuprate superconductivity must be traced on a spectrum prepared by doping with the essential participation of the interband mechanism in the pairing. The appointments that high superconductivity temperatures can be reached in systems where numerous (two) bands interface near the Fermi energy become even more actual. Research Highlights • 55 The author is grateful to P.Rubin and T.Örd for a long-running collaboration. This work was supported by the Estonian Science Foundation grant No 6540 and continued the work done under grant No 4961. REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. K. A. Müller, Physica C 341–348, 11 (2000). N. Kristoffel, P. Rubin, Physica C 356, 171 (2001). N. Kristoffel, P. Rubin, Solid State Commun. 122, 265 (2002). N. Kristoffel, P. Rubin, Physica C 402, 257 (2004). N. Kristoffel, P. Rubin, J. Supercond. 18, 105 (2005). N. Kristoffel, P. Rubin, Proc. Estonian Acad. Sci., Phys. Math. 54, 98 (2005). N. Kristoffel, P. Konsin, T. Örd, Rivista Nuovo Cimento 17, 1 (1994). A. Bianconi, Solid State Commun., 89, 933 (1994). N. Kristoffel, T. Örd, K. Rägo, Europhys. Lett. 61, 109 (2003). T. Timusk, B. Statt, Rep. Progr. Phys. 62, 61 (1999). Ch. Renner et al., Phys. Rev. Lett. 80, 149 (1998). C. Bernhard et al., Phys. Rev. B 52, 10488 (2001). T. Sato et al., Physica C 341–348, 815 (2000). D. Mihailovic et al., Physica C 341–348, 1731 (2000). V. Krasnov et al., Phys. Rev. Lett. 84, 5860 (2000). F. Venturini et al., Phys. Rev. Lett. 89, 107003 (2002). P. Calvani, Phys. Status Solidi b 237, 194 (2003). T. Örd, N. Kristoffel, Phys. Status Solidi b 216, 1049 (1999). N. Kristoffel, T.Örd, P.Rubin, cond-mat/0504431 (2005). H. H. Wen et al., Europhys. Lett. 64, 790 (2003). J. T. Tallon et al., Phys. Rev. B 68, 180501 (2003). T. Schneider, Physica B 326, 283 (2003). N. Kristoffel, P.Rubin, cond-mat/0506317 (2005). N. M. Plakida, High-Temperature Superconductivity, Springer, Berlin, 1995. T. Örd, N. Kristoffel, Physica C 331, 13 (2000). 56 • Biannual Report 2004/2005 How small a packet of photons can be made? Peeter Saari In common non-relativistic quantum mechanics electron wave function can, in principle, shrink into a point at the expense of correspondingly large momentum uncertainty and energy. This is not the case for photon, although solutions of the equations of electromagnetic field can be considered as photon wave functions, as it has been known since 1930.-ies. However, when dealing with narrowband (nearly monochromatic) photon fields, localizability of a photon wavepacket is merely an academic problem. Recent developments in ultrafast and quantum optics and corresponding applications deal with ultrawideband (few- and subcycle) pulsed photon states. Thus, the question – how small a packet of photons can be made? – needs an elaborated treatment. Although the photon wave function in the position space was introduced already in 1930 by Landau and Peierls [1] the concept was found to suffer from inherent difficulties that were not overcome during the century (see review [2]). The common explanation presented in textbooks (e.g.,[3, 4]) may be summed up as follows: (i) no position operator exists for the photon, (ii) while the position wave function may be localized near a space-time point, the measurable quantities like the electromagnetic field vectors, energy, and the photodetection probability remain spread out due to their non-local relation with the position wave function. However, recently both of these widely-espoused notions were questioned and, particularly, Bialynicki-Birula [5] showed that the statement “even when the position wave function is strongly concentrated near the origin, the energy wave function is spread out over space asymptotically like r –7/2 „ (citation from [4], p.~638) is incorrect and that both wave functions may be strongly concentrated near the origin. He demonstrates, on one hand, that photons can be essentially Research Highlights • 57 better localized in space – with an exponential falloff of the photon energy density and the photodetection rates. On the other hand, he establishes that certain localization restrictions arise out of a mathematical property of the positive frequency solutions which therefore are of a universal character and apply not only to photon states but also hold for all particles. More specifically, it has been proven in the Letter [5] for the case of spherically imploding-exploding one-photon wavepacket that the Paley-Wiener theorem allows even at instants of maximal localization only such asymptotic decrease of the modulus of the wave function with the radial distance r that is slower than the linear exponential one, i.e., anything slower than ~exp(–r/l) where l is a constant. The latter is what the Paley-Wiener theorem says about a function whose Fourier spectrum contains no negative frequencies. We have demonstrated [6] that one-photon wave functions (or more generally – N-photon Fock states) of a specific spatial mode type can break the localization restriction and exhibit the linear exponential and even faster (Gaussian) falloff with the distance. Yet, there is no contradiction either with the result of Ref. [5] or with the Paley-Wiener theorem, since the wave functions are cylindrical and exhibit an exceptionally strong localization in two dimensions out of three. Our treatment involves a “technology transfer” in the sense that in order to tackle the problem belonging to quantum electrodynamics, we make use of results obtained recently in the study of the so-called nondiffracting localized solutions to the classical wave equation (see [7–10] and references therein). Without going into mathematical details, the procedure we used was as follows. We took an appropriate localized-wave-type solution to the scalar wave equation and build a Hertz vector of optional direction (polarization) from it. By making use of the circumstance that electromagnetic field vectors can be deduced from the Hertz vector, we expressed the energy wave function of a N-photon number state of the field and calculated its asymptotic dependence of the 58 • Biannual Report 2004/2005 energy spatial distribution on the radial distance r o f from the wave axis. As the first example leading to a stronger localization that one might expect from the Paley-Wiener theorem we considered the photon field where the Hertz vector is directed along the axis z (any other orientation gives similar results) and its strength is given by the scalar function of space and time [8] < ( U , z ,W ) exp§¨ k 0 © U 2 ' iW 2 ·¸ U ' iW 2 ¹ e ik0 z . 2 (1) This expression describes a simple cylindrical pulse modulated harmonically in the axial direction and radially converging to the axis (when the time variable ct { W 0 ) and thereafter (when W ! 0) expanding from it, the intensity distribution resembling an infinitely long tube coaxial with the axis z and with a time-dependent diameter (see Fig. 1). The length parameter determines the radial profile of the function at the instant t = 0. With this function the energy (or photodetection probability) distribution turns out to possess the following asymptotic falloff with the radial distance | F ( U o f, z , W 1 > @ 0) | 2 a U 2 O( U 3 ) exp(2 U / l ) , (2) is the characteristic length (or length unit). Thus, where l k 0 while the photon is delocalized in the axial direction, its energy density falloff in the lateral directions is exactly the linear exponential one. Hence, a one-photon field derived from Eq.(1) serves as a simple example where the localization in two transversal dimensions is governed by different rules than localization in three dimensions according to Ref.~[5]. Figure 1. The cylindrically converging-expanding wave given by Eq. (1). Shown is dependence (a,c) of the real part and (b,d) of the modulus of the wave-function on the coordinate z (increasing from the left to the right) and on a transverse coordinate x = ± at two time instants: (a,b) ct = 0 and (c,d) ct = l . Distance between the grid lines on the basal plane (x,z) is l. The grey-scale plots of | (x,z,t)| are normalized to “white” at the plot maximum, so that the “white” level in the plot (d) is actually 5 times weaker than in plot (b). The grey shading in plots (a) and (c) is a result of “lighting” used for better revealing the relief of the surface. Figure 2. The superluminal FXW. Shown is dependence (a) of the real part and (b) of the modulus of the wavefunction on the longitudinal and trans-verse coordinates. The modulus propagates rig-idly from the left to the right along the axis z with a superluminal speed [8,10]. Research Highlights • 59 Other localized waves are readily available via the Lorentz transformation of the wave function given by Eq.(1) along the axis z. One of such – the so-called focused X wave (FXW) is depicted in Fig. 2. The strongly localized waist and the whole amplitude distribution move rigidly and without any spread along the axis z with a superluminal speed. It should be noted here that there is nothing unphysical in the superluminality of the localized waves – which is, moreover, an experimentally verified fact – since a superluminal group velocity does not mean as if information could be transmitted faster than c [7]). For the FXW in the waist region (see Fig. 2) the photon energy distribution has the same radial falloff as was given by Eq. (2), while the axial localization follows a power law. Hence, in its waist (cross-sectional) plane a one-photon (or N-photon) field derived from the FXW possesses the same strong localization at any time as the previously considered cylindrical field does in any transversal plane any transversal plane at the instant t = 0. Another localized wave derivable from Eq.(1) – the so-called focus wave mode (see reviews [7,9] and references to the pioneering papers of 1980.-ies therein) – leads to even stronger localization of the photon energy. Namely, in this case the photon localization in the waist plane turns out to be quadratically exponential (Gaussian falloff): | F( U o f, z W ) | 2 a U 6 exp( U 2 / la ) . It could be argued that the well-known Gaussian beam pulse has the same quadratically exponential radial profile in the waist region. However, resorting to the family of the Gaussian beams (the GaussLaguerre and Gauss-Hermite beams, etc.) is irrelevant here. The reason is that all these beams are solutions of the wave equation only in the paraxial approximation not valid in the case of any significant localization of wide-band (pulsed) superpositions of the beams, whereas in fact, e.g., an exact solution corresponding to a lowestorder (axisymmetric) Gaussian beam has a weak power-law radial falloff in the waist region [11]. 60 • Biannual Report 2004/2005 In conclusion, we have shown that for certain cylindrical N-photon states (N = 1,2,…) the localization in lateral directions breaks not only the restrictions known from the textbooks but also that established in Ref. [5] for the case of uniform spherical photon wave functions. Our new results hold not only for photons but for number states of any particles and throw new light on the localization of the quantum fields. REFERENCES 1. L. D. Landau and R. Peierls, Z. Phys. 62, 188 (1930). 2. I. Bialynicki-Birula, Photon wave function, in: E. Wolf (Ed.), Progress in Optics, vol. 36, North-Holland, Amsterdam, 1996. 3. A. L. Akhiezer and V. B. Berestetskii, Quantum electrodynamics, Interscience, New York, 1965. 4. L. Mandel and E. Wolf, Optical Coherence and Quantum Optics, Cambridge University Press, Cambridge, 1995. 5. I. Bialynicki-Birula, Phys. Rev. Lett. 80, 5247 (1998). 6. P. Saari, M Menert, and H. Valtna, Opt. Commun. 246, 445 (2005). 7. P. Saari and K. Reivelt, Phys. Rev. Lett. 79, 4135 (1997). 8. P. Saari and K. Reivelt, Phys. Rev. E 69, 036612 (2004). 9. K. Reivelt and P. Saari, in: arXiv, physics/0309079. 10. H.Valtna, K.Reivelt and P.Saari, J. Opt. A: Pure Appl. Opt., 8,. 118 (2006). 11. P. Saari, Opt. Express 8, 590 (2001). Multiphoton processes in intense laser fields Viktor Peet In recent years, interesting and unusual features of the so-called nondiffractive or propagation-invariant light beams have attracted considerable interest in applications of such beams in nonlinear optics. In most cases the simplest coherent conical beams like Bessel Research Highlights • 61 beams were used, but much less is known about nonlinear optical processes driven by incoherent conical beams. Recently several evidences have been found that conical excitation geometry allows one to preserve a relatively high efficiency of a nonlinear process even for laser beams with significantly degraded beam quality. Such a tolerance may be very interesting and useful feature of conical beams in the excitation of nonlinear optical processes and frequency conversion of laser emission. Resonance-enhanced four-wave mixing and generation of sumfrequency field in xenon have been studied under two-color excitation by spatially coherent and incoherent conical laser beams. Comparisons of analogous results with a two-color excitation in an ordinary geometry of focussed beams and in one-color Bessel beams have been made. It has been shown that with incoherent laser beams the fourwave mixing process is much less degraded in conical excitation geometry where an efficient generation of sum-frequency field can be obtained despite of multiple wave-front aberrations. Such a tolerance of conical beams results from their specific structure of coherent focal domains that are extended significantly along the beam axis. It preserves a relatively high degree of coherence for excitation processes even for input beams with poor spatial coherence. Numerical simulation of sum-frequency excitation profiles for one- and two-color conical beams has been carried out and good agreement with experimental observations has been obtained. REFERENCE V. Peet and S. Shchemeljov, Sum-frequency generation and multiphoton ionization in spatially incoherent conical laser beams, Optics Commun. 246, pp. 451–463, 2005. 62 • Biannual Report 2004/2005 Decay of Anion and Cation Excitons into Frenkel Pairs and Defect Triplets in LiF Single Crystals Aleksandr Lushchik For a long time, wide-gap LiF crystals (Eg # 14.2 eV) have been used as optical materials and tissue-equivalent dosimetric materials. In LiF, the creation energy of anion and cation excitons equals Ea # 13.1 [1] and Ec # 62 eV [2], respectively. However, the processes of anion or cation exciton decay into elementary radiation defects is studied insufficiently. In 2004–2005 we performed a complex study of these processes using the methods of VUV spectroscopy (photon energy up to 70 eV) and thermoactivation spectroscopy in a temperature range of 4.2–750 K [1,3–6]. Low-temperature decay of anion excitons with the formation of Frenkel pairs (F-H pairs) has been thoroughly studied and compared with that in earlier investigated KCl and KBr crystals. The decay of a cation exciton into an anion one and several electron-hole (e-h) pairs has been revealed as well. In the latter case spatially correlated electronic excitations can be transformed into a defect triplet, which is stable at 4.2–11 K and undergoes destruction by a heating up to 16 K. Fig. 1 shows the reflection spectrum and the excitation spectra for the 3.4 and 4.2 eV emissions measured for a LiF crystal at 9 K. The growth procedure of this highly pure crystal is described in [3]. The 3.4 eV emission of self-trapped excitons (STEs) is efficiently excited at the direct formation of anion excitons by the photons of hQex = 12.4–14.0 eV as well as in the region of band-to-band transitions (hQex > Eg). A narrow excitation band at 12.2 eV can be also detected in the excitation spectrum for 4.2 eV emission. The 4.2 eV emission is excited neither at hQexc < 11.8 eV nor in the whole region of fundamental bulk absorption, that is untypical of impurity or defect-related emissions in LiF. According to theoretical calculations [7], the absorption of the excitons at a clear and flat (100) Research Highlights • 63 surface of LiF is peaked at 12.3 eV. The inset shows normalized emission spectra measured for LiF at the photoexcitation selectively forming bulk anion excitons or e-h pairs (13 and 16.2 eV photons, respectively). The impurity/defect emission in the region of 4.5–5.9 eV (see inset) is excited by photons of 10 to 11.8 eV as well as in the region of hQex > Eg. It should be mentioned that the emission and excitation spectra change drastically in a LiF sample preirradiated at 295 K by krypton swift heavy ions (820 MeV, 5u1011 Kr/cm2) using the linear accelerator UNILAC of the GSI, Darmstadt. The efficiency of the emission connected with the localized surface excitons is sharply reduced in the region of 12.2 eV in the case of distorted crystal surface. Figs. 2a and 2b present the curves of thermally stimulated luminescence (TSL) in the region of 5–200 K measured for a LiF crystal irradiated by electrons at 6 K. The analysis of the data obtained by several experimental methods allowed to conclude that the TSL peaks at 28–30 K are connected with the annealing of I centres (F– interstitial ions), while the peaks at 38–40 and 50–60 K are caused by the reorientation and hopping migration of H centres, respectively. At 50–60 K a mobile H interstitial recombines with a two-electron Fc centre and a released conduction electron subsequently participates in the radiative recombination with a localized hole. A similar process occurs at 100–115 K, when an H interstitial gets free from an impurity trap (even in a pure LiF some cations are replaced by Na+ ions). The obtained TSL data as well as additional direct measurements of temperature dependence of the radiationinduced absorption spectra and literature data on EPR and ENDOR of H and HA centres confirm the decay of an anion STE into an F-H pair in the LiF crystal. According to Figs. 2b and 2c, H and HA interstitials are created at the direct optical formation of anion excitons by 13.8 eV photons or at the recombination of electrons with self-trapped holes (VK centres, hQexc = 17 eV). The efficiency of F-H pair creation by VUV radiation at 4–8 K is low. In many alkali 64 • Biannual Report 2004/2005 halides dihalide H interstitials are oriented along closely-packed <110> anion rows and a low-temperature crowdion mechanism of interdefect separation inside F-H pairs provides defect stabilization (see [4] and references therein). However, such crowdion mechanism in LiF and NaCl is impossible because of the orientation of H centres along <111> and a considerable spatial separation of F and H centres, formed at a STE decay, is impeded. The efficient removal of an H centre from an F centre becomes possible at T > 50 K due to a hopping diffusion of H centres. At a slightly higher temperature (T > 60 K) the mobile H centres interact with VK centres resulting in the formation of F3– molecules (an absorption band at 11 eV) stable in LiF up to a500 K [3]. Several TSL peaks were detected in a LiF crystal irradiated at 8 K by 62 eV photons selectively creating cation excitons (see Fig. 2c): the 110 K peak is connected with the decay of HA centres, TSL at 130–140 K is accompanied by the annealing of the EPR signal of VK centres, the thermal ionisation of Fc centres takes place at 155–160 K. The Fc-TSL peak can be also registered after the direct optical formation of anion excitons. Of particular interest is the origin of the intense 13 K TSL peak in irradiated LiF crystals (see [1,3,6]). The intensity of this peak is especially high after the irradiation of LiF by X-rays (30–50 keV) or 1.5–30 keV electrons, while the 13 K TSL peak cannot be induced after selective photoexcitation forming anion excitons (hQexc = 12.5– 14 eV) or separated electrons and holes (hQexc = 17 eV). In our opinion, the creation of a group of spatially correlated electronic excitations by a VUV exciting photon is needed for the appearance of the 13 K peak. In KBr and KCl, such excitation group can be created by an exciting photon whose energy is sufficient for the formation of a valence hole and a hot conduction electron. The hole undergoes selftrapping, while the electron creates a secondary anion exciton decaying into an F-H pair nearby a self-trapped hole. The subsequent Figure 1. The reflection spectrum () and the excitation spectra of 3.4 (xx) and 4.2 eV emission () for a LiF crystal at 9 K. The spectra were measured for a time-integrated (TI), fast (f, a time window of 't = 8 + 26 ns) and slow component (s, 't = 52 + 148 ns). A vertical arrow indicates the calculated energy of surface excitons [7]. The inset shows emission spectra at the crystal excitation by 13 eV (1) and 16.2 eV photons (2) at 9 K. Figure 2. The thermal annealing of the decay products of anion and cation excitons in a LiF crystal irradiated at 6–8 K. The annealing of the EPR signal of VK centres (1). The TSL curves measured for 3.4 eV (2), 4.6 eV (3), 5.4 eV emissions (4) or an integral signal (5–7) at the heating (E = 10 K/s) of the sample irradiated by 13.8 eV (5), 17 (6) and 62 eV photons (7), 30 keV electrons (2, 2c, 2cc, 4) or X-rays (50 keV, curve 1). Research Highlights • 65 trapping of an electron by an H centre results in the formation of an F-I-VK defect triplet (see, e.g., [8]). The 13 K TSL peak can be formed after the irradiation of LiF at 8 K by 62 eV photons selectively creating cation excitons [6]. The energy of 2–30 keV electrons is insufficient for the realization of the knock-out (impact) mechanism of defect creation – even the lightest of possible impurity ions (hydrogen) cannot be removed from lattice sites by such electrons. Doping of LiF with Na+ or Mg2+ ions with the concentration higher than 100 ppm leads to a significant decrease of the intensity of the 13 K TSL peak [1,6]. This peak can be also suppressed by additional stimulation of the irradiated sample at 8 K by the photons causing photoionization of Fc centres. Such Fc-illumination simultaneously leads to the appearance of a rapidly dumping out with time photostimulated luminescence (PSL) at 5.7, 3.4 and 2.9 eV. Fig. 2a shows the TSL curves measured for 5.4 and 3.4 emissions connected with the direct or stepwise tunnel recombination of either of two electrons from an Fc with a VK centre. According to Fig. 2a, the ~13 K TSL peak has a complex structure. A lowtemperature component is efficiently detected for 5.4 eV emission caused by the direct tunnel recombination of an electron from an Fc centre with a VK centre. The emission of STEs (3.4 eV) arises due to the tunnelling of an electron from an F or Fc centre to a VK via an excited triplet exciton state. Fig. 2a demonstrates two components of TSL at ~13 K measured for 3.4 r 0.1 eV emission (curves 2c and 2cc). The analysis of the above-mentioned results allowed us to conclude that the cation exciton in LiF decays into an anion exciton (~13 eV), while the rest of the energy (~49 eV), after intermediate processes connected with the formation of a photon or an Auger electron, is expended by creating up to three e-h pairs. A shortwavelength analogue of the Raman effect, when excitons act as phonons at the scattering of X-rays, was theoretically considered by Agranovich and Ginzburg back in 1961 [9]. Previously we experimentally revealed (see, e.g., [4]) the decay of a cation exciton 66 • Biannual Report 2004/2005 (Ec # 34 V) into one anion exciton (Ea # 8 V) and two e-h pairs in NaCl crystals. According to Kamada et al. [10], the ejection efficiency of lithium atoms in an excited state from LiF is practically equal in magnitude for the cases of crystal irradiation by 13 eV or 62 eV photons. The latter result confirms the decay of a cation exciton with the formation of an anion one. This free anion exciton undergoes self-trapping with the subsequent decay into an F-H pair. The decay of a cation exciton in LiF at 8 K causes the formation of an F-H pair, spatially separated by several interion distances a VK centre and a conduction electron. This group of electronic excitations transforms mainly into a triplet of spatially correlated defects – Fc-H-VK. A further detail study of the decay of cation excitons with the formation on anion ones in radiation-resistant materials (e.g., MgO), where the formation energy of a Frenkel pair exceeds the value of Eg, lies ahead. This work has been done in collaboration by V. Babin, E. Feldbach, M. Kirm, A. Kotlov, T. Kärner, I. Kudryavtseva, P. Liblik, A. Lushchik, Ch. Lushchik, S. Nakonechnyi, V. Nagirnyi, E. Vasil’chenko (IPUT) and L. Pung (Physics Department, Tartu University). REFERENCES 1. S. Nakonechnyi, T. Kärner, A. Lushchik, Ch. Lushchik, V. Babin, E. Feldbach, I. Kudryavtseva, P. Liblik, L. Pung, E. Vasil’chenko, J. Phys.: Condens. Matter 18, 379 (2006). 2. A. M.-E. Saar, A. A. Maiste, M. A. Elango, Sov. Phys. Solid State 15, 1663 (1974). 3. E. Vasil’chenko, I. Kudryavtseva, A. Lushchik, Ch. Lushchik, V. Nagirnyi, Phys. Status Solidi c 2, 405 (2005). 4. M. Kirm, A. Lushchik, Ch. Lushchik, Phys. Status Solidi a, 202, 213 (2005). Research Highlights • 67 5. A. Lushchik, A. Kotlov, Ch. Lushchik, V. Nagirnyi, K. Schwartz, 6. 7. 8. 9. 10. E. Vasilçhenko, In: HASYLAB Activity Report 2005, Part I, DESY, Hamburg, Germany, p. 257. A. Lushchik, Ch. Lushchik, M. Kirm, V. Nagirnyi, F. Savikhin, E. Vasil’chenko, Nucl. Instr. and Meth. B (2006) accepted. N.-P. Wang, M. Rohlfing, P. Krüger, J. Pollmann, Phys. Rev. B 67, 115111 (2003). M. Kirm, A. Lushchik, Ch. Lushchik, I. Martinson, V. Nagirnyi, E. Vasil’chenko, J. Phys.: Condens. Matter 10, 3509 (1998). V. M. Agranovich, V. L. Ginzburg, Sov. Phys. JETP 13, 683 (1961). M. Kamada, N. Takahashi, S. Hirose, 1999 J. Electron Spectrosc. Relat. Phenom. 101–103, 599 (1999). Resonant Inelastic X-ray Scattering at the F 1s photoabsorption edge in LiF 1 1 Arvo Kikas,1 Tanel Käämbre, Agu Saar,1 Kuno Kooser, Ergo 1 2 Nõmmiste, and Indrek Martinson 1 Institute of Physics, University of Tartu, Riia 142, EE-51014 Tartu, Estonia 2 Department of Atomic Spectroscopy, Lund University, Professorsgatan 1, S-22100, Lund, Sweden Resonant inelastic X-ray scattering spectroscopy (RIXS) has in recent years attracted attention as a source capable providing a unique variety of information about the electronic structure of solids. For example, it has been shown to be a particularly useful technique when investigating the structure of the valence and conduction band electronic structure in high-symmetry carbon compounds and the charge transfer induced processes in transition metal compounds. Here we present the results of a study of threshold processes at the F 1s photoabsorption edge by RIXS. Solid LiF is an ionic compound, in which the chemical bond is constituted by the electrostatic forces between the Li+ and the F– ions. The F1s photoabsorption spectrum 68 • Biannual Report 2004/2005 of LiF has a wide threshold peak, whereas generally in ionic solids the sharp excitonic pre-threshold peaks tend to dominate. However, it has recently been shown that the photoabsorption spectrum of LiF cannot be calculated without taking the electron-core hole interaction into account [1]. Experimentally, the spectral features, which stem from a core exciton have been identified in the resonant Auger spectra [2] and in the non-resonant inelastic X-ray scattering spectra [3]. The experiments described in this report were performed at the “bulk” branch of beamline I511. Typical resolutions used were 0.3 eV (100 µm exit slit) for the SX700 monochromator at the beamline and 0.3 eV for the Rowland circle mounted X-ray emission spectrometer on the endstation. The sample was a LiF single crystal. The incidence angle of the incoming light was set to 60 degrees. Figure 1 gives an overview of the measured X-ray emission spectra for the excitations in the vicinity of the F 1s photoabsorption threshold. The top curve in Figure 1 displays a fluorescence spectrum at non-resonant excitation. The fluorine K X-ray emission peak is seen at 677.8 eV. This emission is due to transition, where electron from valence band fills inner shell hole (see energy scheme at Fig. 2). In the 681–682 eV energy range, a satellite peak appears, which originates from an initial state containing an additional vacancy in the valence band. These satellites appear for excitation energies above approximately 720 eV. It can be seen that the spectra, measured at low excitation energies, consist of two different kinds of structures. One of these remains at constant emission energy (677.8 eV) which coincides with the F K characteristic X-ray emission line. The other one is a wide band which shifts to higher energies together with the excitation energy at approximately constant energy loss. The latter thus behaves in a manner characteristic of the radiative (Raman) inelastic X-ray scattering. At the photoabsorption threshold this structure merges into the K characteristic emission line. Note that the half width of this merged peak changes significantly at the threshold. The presence Research Highlights • 69 of the K fluorescence peak in pre-threshold spectra refers to the circumstance, that at these photon energies the photons from the tail of the incoming photon energy distribution excite the characteristic K fluorescence. In order to better understand these spectra we performed a simple simulation based on the Kramers-Heisenberg formula. Two different calculations have been performed. A strict approach has presented in Ref [4]. Here we present a simpler model, which bases on the approach, previously used for the resonant Auger spectra of Ag and Cu metals [4, 6]. By the resonant scattering theory, the energy distribution I (!Z in , !Z out ) of the outcoming photons !Z out for the excitation energy !Z in can be written in the following way: I (!Z in , !Z out ) U (e) N ph (!Z in !Z )ded!Z 2 2 2 2 > @> @ 0 0 (!Z e E K ) *K / 4 (!Z e !Z out E L ) *L / 4 ff C³ ³ where U is the density of final states, N ph is the experimental photon energy distribution, *K and *L are lifetime widths of the corresponding levels, E K and E L are binding energies of the corresponding levels, C is the scale factor, which includes matrix elements. In this simulation we take into account the scattering on the bound (excitonic) and the free (conduction band) states. For this we approximate the conduction states with a step function while an additional Gaussian function at 1.25 eV below the onset of the conduction states is taken as an approximate description of the excitonic states (see Fig. 2). The energy distribution of the incoming photons has been approximated as a sum of Gaussian and Lorentzian functions with the intensity ratio of 4:1. Such shape of the latter distribution is crucial for the agreement with the pre-threshold spectra, because without the Lorentzian component the simulation does not reproduce the emission intensity at 677.8 eV for the prethreshold excitation. The results of this simulation are presented in 70 • Biannual Report 2004/2005 Figure 3. It is seen that the form of the experimental spectra is reproduced, as well as the measured changes in the peak widths. Note, that in calculated spectra (a) and (b) there is a peak between the scattered peak and characteristic K fluorescence, which is barely seen in experimental spectra. This peak is a result of scattering on the excitonic state and it merges into the K fluorescence peak in spectrum (c), causing the shift and broadening of the resulting peak. Similarly in spectrum (e) the shift and broadening of the emission peak is result of merging of the K fluorescence peak with the peak originating from the scattering on conduction states. However, the simulated spectra are somewhat narrower than the experimental. The reason for this are probably that the phonon broadening is not taken into account in the simulation. Neither does the simulation reproduce the low energy shoulder in the emission spectra. This may be due to the circumstance that the density of valence states is not taken into account in simulation. Note, that this simple approach gives a result, which agrees well with the more strict approach of Ref. [4]. We note that the particular amount of the ‘Lorentzian contribution’, simulating the extended energy tail(s) of the monochromator function, should firstly be seen as an aberration from the fully Gaussian energy distribution in the transmission of an ideal monochromator – thus the particular amount of the Lorentz contribution depends on the particular physical machine that is used and the parameters therein. The non-negligible contributions from higher diffraction order light from the monochromator can be out-ruled in this experiment, since placing the monochromator energy approximately 100 eV below the F 1s excitation threshold resulted in nondetectable (i.e., below the noise level) F K emission from the sample. It is interesting to note, that the RIXS spectra at F 1s edge in LiF differ from the case of O 1s edge MgO, because an additional narrowing of the X-ray fluorescence peak was not observed in MgO, which can be related to the absence creation of a core exciton in the case of sub-threshold excitation in MgO [7]. PFY TEY d g c f b a h e 690 695 700 705 hQin [eV] n h g f e d c b a 665 670 675 680 685 X-ray emission energy [eV] Figure 1. The scattering spectra recorded at excitation energies (see inset) in the fluorine 1 s absorption resonance range. Inset: the 1s photoabsorption profile of LiF showing the excitation energies for the RIXS spectra. The excitation energy for spectrum n is 732 eV. Figure 2. Scheme of transitions for resonantly excited F K X-ray fluorescence in LiF. Excitonic Continuum Total g f e d c b a 672 674 676 678 X-ray emission energy [eV] Figure 3. The calculated RIXS profiles, corresponding to the excitation energies used in the experiment (see Fig. 1). Research Highlights • 71 Our RIXS spectra allow to identify a single core exciton in LiF, similar to the results obtained using non-resonant X-ray scattering [3]. On the other hand, core excitons were detected in resonant Auger spectra at excitation energies 690.5 and 691.7 eV [2]. This controversy can be solved by assuming that the higher energy core exciton state, which is observed in RAS, is a result of the postcollision induced recapture of a slow photoelectron. This mechanism has been previously discussed in the case of Na 1s excitations in NaF [8]: right above the 1s ionization limit, the outgoing photoelectron can be recaptured into bound state by post-collisional interaction with a fast Auger electron. As a result, in the resonant KLL Auger decay spectra a new peak appears, which is shifted to higher kinetic energies as compared to the normal Auger peak. Because such an interaction is not possible in the case of radiative decay, we do not observe the corresponding exciton in the radiative decay spectra, and so it cannot either be seen in the non-resonant X-ray scattering spectra of LiF. REFERENCES 1. Eric L. Shirley, Phys. Rev. Lett. 80 (1998) 794–797. 2. H. Aksela, E. Kukk, S. Aksela, A. Kikas, E. Nõmmiste, A. Ausmees, M. Elango, Phys. Rev. B, 49 (1994) 3116. 3. K. Hämäläinen, S. Galambosi, J. A. Soininen, E. L. Shirley, J.-P. Rueff, and A. Shukla, Phys. Rev. B, 65 (2002) 155111. 4. A. Kikas, T. Käämbre, A. Saar, K. Kooser, E. Nõmmiste, I. Martinson, V. Kimberg, S. Polyutov, and F. Gel’mukhanov, Phys. Rev. B, 70, 085102 (2004). 5. W. Drube, R. Treusch, and G. Materlik, Phys. Rev. Lett., 74 (1995) 42. 6. A. Föhlisch, O. Karis, M. Weinelt, J. Hasselström, A. Nilsson, and N. Mårtensson, Phys. Rev. Lett., 88 (2002) 027601. 7. A. Kikas, T. Käämbre, V. Kisand, A. Saar, K. Kooser, E. Nõmmiste, I. Martinson, J. Electron Spectrosc. and Relat. Phenom, 144–147 (2005), 845. 8. A. Kikas, E. Nõmmiste, R. Ruus, A. Saar, I. Martinson, Phys. Rev. B, 64 (2001) 235120. 4. SCIENTIFIC REPORT Laser spectroscopy and applications of photosensitive materials The main directions of the reasearch were high resolution spectroscopy (including single molecule spectroscopy and spectral hole burning) of solid phases (glasses, incommensurate systems), synthesis and spectroscopy of layered structures, modelling of dynamics of biomolecular structures, search of applications for the materials and phenomena under consideration. The reference number are those of the list of Section “Publications”. Spectroscopy and applications of metal oxide films doped with rare earth ions J. Aarik, V. Kiisk, S. Lange, H. Mändar, I. Sildos A novel method of preparation of optical films was developed, based on growth of metal oxide (TiO2; ZrO2, HfO2) nanolayers of controlled thickness by atomic layer deposition or sol-gel technique. ALD films were doped with luminescent rear-earth ions (Sm3+, Eu3+, Tb3+) by ionic implantation, sol-gel materials were doped by adding respective salt to the educt compounds. The materials obtained were characterized by x-ray diffraction and Raman scattering, the surface of the films was studied with nanoresolution using an atomic force microscope. It was shown, that the doping reduces the size of nanocrystallites. Luminescent characteristics of the materials were Scientific Report • 73 studied using for excitation both UV lasers (193, 248, 355 nm) and synchrotron radiation in VUV in Hamburg. Due to good spectral and temporal characteristics of excitonic self-emission of ZrO2 and HfO2 (UV, decay times of nanoseconds) these materials have prospective applications as soft x-ray scintillators. It was shown, that UV absorption in the fundamental absorption band of these materials is accompanied by an efficient energy transfer, resulting in excitation of the rare-earth impurity ions and leading to characteristic luminescence of these ions. By using a saturation technique an effective cross-section of 10 –15 cm2 for this excitation channel was estimated. It was shown that novel luminescent materials can be developed based on the systems studied. In Sm3+-doped TiO2 films sensitivity of the impurity emssion to the oxygen content in the surrounding gas was found, promising applications in sensorics. Usage of Sm3+:TiO2 layers as waveguides for optical emission was demonstrated. Dependence of the exciton as well as impurity luminescence in a thin anatase (TiO2) film on the waveguide characteristics (thickness, substrate material) was studied and modelled. The structure of the waveguide determines formation of specific spectral peaks and polarizational characteristics in the leak modes of the layer. In the spectra of nitrogen-doped diamonds an experimental evidence was found for theoretical results (V. Hizhnjakov, H. Kaasik) on peculiarites of the phase relaxation in impurity ions in a situation of dynamical instability. As a main instrumental development implementation of a confocal Raman-fluorescence microscope should be mentioned, yielding lateral and axial resolutions of 3,3 Pm and 14 Pm, respectively. Its operational parameters were tested by measurement of the distribution of nickel-nitrogen (NE8) impurity centres in a diamond crystal. Such defects were shown to be located in a surface layer of 200 Pm thickness due to their formation in an annealing process. [22, 27, 41, 155, 159, 220] 74 • Biannual Report 2004/2005 Laser probing of critical phenomena and single-molecule dynamics in incommensurate biphenyl An. Kuznetsov, A. Laisaar, V. Palm, M. Pärs, A. Suisalu By reducing the critical temperature of a structural phase transition with application of hydrostatic pressure an anomalous behavior of pyrene dopant spectra in incommensurate biphenyl was observed. The photoluminescence spectra of pyrene dopant were studied for temperatures of 4.7–40 K at pressures of 0.2–2.0 kbar. Temperature dependence of a dublet splitting of the pyrene 597 nm emission line was observed in the first incommensurate phase. From these data the pressure dependence of the phase transtion temperature between the commensurate and the first incommensuret phase was established. Interesting results were obtained for the low-temperature region of quantum fluctuations (T < 10 K), where the phase transtion pressure (Pc ~1,8 kbar) is practically independent on temperature. In this region (from 4.7 to 10 K) an anomalous contraction of spectral line was observed with increasing tempearture, converting further (for (10–40 K) to a “normal” temperature broadening. [63] Novel samples for single molecule spectroscopy – thin (of several microns thickness) pyrene-doped monocrystals of biphenyl – were grown by cosublimation at 180o C in an inert gas environment. The samples exhibit terrylene single-molecule lines of intensity exceeding by an order of magnitude those in polycrystalline samples. As a result, a better temporal resolution for recording the spectra was reached, used to measure fast processes of spectral diffusion in cooperation with the University of Lund. [48] Scientific Report • 75 Temperature and pressure effects on impurity spectra in glasses and mixed crystals J. Kikas, An. Kuznetsov, A. Laisaar, I. Renge, A. Suisalu, U. Visk Results on pressure reduction of the residual hole broadening in temperature cycling experiments in a polymeric (polystyrene) glass were interpreted within a common theoretical frame, developed earlier for isothermal hole burning. A key ingredient in the interpretation is an assumption about asymmetric distribution of the asymmetry parameter in the soft potential model for excitations in low-temperature glasses (collaboration with V. Hizhnyakov). In a Sm2+-doped Na-borate glass (33 Na2O – 66 B2O3) an anomalous linear temperature dependence of the homogeneous spectral width of impurity 7F0 l 5D0 electronic transition was observed and interpreted. The homogeneous width was measured by spectral hole burning and fluorescence narrowing techniques for temperatures 5 293 K at normal pressure and for temperatures 5, 80 and 120 K at various pressures up to 8 kbar. The observed at T > 20 K linear (v T) temperature dependence was interpreted by a modulation broadening of the electronic transition by low-frequency localized vibrational modes. In the Na-boron glass such a mechanism prevails over the standard two-phonon process of dephasing. Under the applied hydrostatic pressure the inhomogeneous 7F0 l 5D0 transition band at 684 nm in the above systems shifts to longer wavelengths. Surprisingly, such a shift is larger at 77 K compared to the room temperature value (0.066 vs 0.041 nm/kbar, respectively). Unusual observation is also a temperature narrowing of the inhomogeneous band (4.4 nm at RT, compared to a value of 5.4 nm at 77 K). The established absence of an observable pressure narrowing of homeogenous spectral lines in the borate glass calls for an extension of the existing theoretical models (cooperation with the University of Erlangen-Nuremberg). 76 • Biannual Report 2004/2005 A detailed study of pressure dependence of Sm2+ dopant photoemission spectra in Ba12F19Cl5–xBrx : Sm2+ (x ~ 1) mixed crystal up to 7 kbar was carried out for 80 and 121 K, revealing a pressure-induced narrowing of the inhomogeneous spectral band (collaboration with R. Jaaniso). Possibilities to determine and predict homogeneous and inhomogeneous characteristics of dopant spectra as functions of temperature (up to 300 K) and pressure were analysed, including situations where the 0–0 line is spectrally not resolved. As a starting point for extrapolations low-temperature (5–50 K) and low-pressure (up to 200 bar) characteristics of spectral holes in solvent glasses and polymers were used. The temperature-induced narrowing of the site energy distribution due to the thermal expansion of matrix was pointed to as a counterbalancing factor to the temperature-induced broadening of spectra. Qualitative features of the effects were described in a simple model using Lennard-Jones potentials. [53,158, 201] Quantum chemical modelling of fluorescence and conformational dynamics of BFP K. Mauring, V. Krasnenko Using quantum-chemical calculations differences of the excited state lifetime in two conformations of the blue fluorescent protein (BFP) were attributed to formation of hydrogen bonds. From the experimental results on influence of temperature and pressure on the intensity of fluorescence and on the excited state lifetime, two different conformation of BFP were shown to exist, distinguished by existence or absence of hydrogen bonds between the chromophore and adjacent amino acids. At decreasing temperature or increasing pressure the ratio of the hydrogen-bonded conformations increases, resulting in an increase of the fluorescence intensity and of the exited state lifetime. The question, why the fluorescence from the non-bon- Scientific Report • 77 ded conformation is strongly quenched, was answered by quantumchemical calculations. Upon absorption of a light quantum, the chromophore is transferred to a quite unstable excited state, where the forces induced by redistribution of the electron density try to deform it. As a result, the adiabatic energy surfaces of the ground and excited state approach each other (or even intersect), quenching the fluorescence. The hydrogen bonds, however, make the chromophore more rigid and reduce the twist deformation, increasing thus the yield of fluorescence. Prospects for using this effect for sensing temperature and pressure were analysed. [186] Spectral sensing and environmental analysis A. Suisalu, K. Rebane, M. Kleemann, J. Kikas A moisture-sensitive polymer membrane was developed and characterized, based on polymethyl-metacrylate (PMMA) film doped with solvatochromic Reichardt’s betaine dye. The sensing effect stems from a hyperchromic effect and a hypsochromic shift of the absorption spectra. It was shown that a common model of dual gas sorption applies to the dynamics of water molecules in the glassy PMMA. A method was implemented for a highly sensitive fluorescent analysis of cancerogenes and other compounds in water, including sample extraction, processing and spectroscopic measurements in frozen n-alkanes (Shpolskii matrices), aiming at a sensitivity level of single-molecule detection. [246] Compiled by Jaak Kikas 78 • Biannual Report 2004/2005 Nanostructured materials This project centers on the application of atomic-layer-deposition, pulsed-laser-deposition, and sol-gel methods for the nanodesign of solids. Different coatings, insulator materials, materials for gas sensing, fibers, etc. are studied, nanoscale measurement techniques advanced, and theoretical approaches worked out. Two years’ results of the five research groups involved are as follows. For the group including J. Aarik (leader), A. Aidla, J. Asari, A. Gerst, A.-A. Kiisler, H. Koppel , M. Lulla, R. Lurich, A. Niilisk, R. Pärna, R. Rammula, P. Ritslaid, A. Rosental, V. Sammelselg (Institute of Physical Chemistry), A. Tarre, and T. Uustare: HfO2 films, atomic layer deposited on Si substrates were compared. It was shown that at temperatures above 450°C the growth from HfCl4–H2O starts in an inhibited way, in the form of threedimensional islands. Since the thickness of 2–3 nm, the films contained a cubic HfO2 crystal phase. The initial growth turned faster and more two-dimensional when a 1–2-nm-thick buffer layer deposited at 300 °C was used. Upon transfer to the HfI4–H2O or HfI4–O2 precursor pairs, considerably more homogeneous ultrathin films were obtained. Along with the improvement in the homogeneity of the films, there was a decrease in the ratio of the crystal phase to the amorphous phase ratio in the films and an improvement in the film smoothness. At temperatures 180–300 °C, the growth turned sufficiently fast and steady already at thicknesses below 1 nm. It was shown that, in the beginning, the growth of HfO2 films on Si substrates covered with Pt, Ir, and Ru layers was substantially less inhibited than that on the pure or chemical-oxide-covered Si substrates. Also, the stationary growth rate was then higher and the creation of the crystal phase faster. In our atomic layer grown HfO2–Si, Al2O3–Si, and TiO2–Mo structures interesting from a point of view of microelectronics, almost Scientific Report • 79 always a transition layer of up to 3 nm was revealed between the substrate and the film. The layer consisted of a mixture of the oxide that was deposited and the oxide of the substrate material (Si or Mo). In the case of HfO2, it was found that at temperature 225°C the growth of the material started in the amorphous phase and the signs of crystallization appeared only in the course of the growth. The process continued so that the part with a crystallized cubic structure grew faster than the amorphous part. In the films grown at 300°C, a layer of less than 5 nm was amorphous and in the rest of the film, the existence of the monoclinic phase was registered. The films, grown at temperatures 350–750°C, contained the monoclinic phase all through the film. Importantly, it turned out that the HfO2 films grown in the range of 350–400°C did not have a transition layer of a mixed oxide. It was ascertained that in the initial phases of the atomic layer growth of ZrO2 (deposition temperature 500°C), there formed and dominated the metastable tetragonal phase. Upon further growth, the content of the phase stayed almost constant, but its proportion decreased due to the addition of the stable monoclinic phase. With the increase of the pressure and flow rate of the carrier gas (N2), a slow-down of atomic layer deposition of ZrO2 and HfO2 films was observed. The HfO2 films grown at a higher flow rate contained more metastable phase and less chlorine, a residue from metal precursors (HfCl4 or ZrCl4). The surface of these films was smoother and their refractive index higher. The effect of the carrier gas was associated with the changes in the concentration of the metal-precursor and OH groups on the surface of a growing film. When depositing gas sensitive SnO2 films on –Al2O3(0 1 2) substrates from the precursor pair SnI4–H2O2, an acceptable atomic layer growth rate was achieved in a temperature range of 100–600°C. In the case of the precursor pair SnI4–O2, the respective range started at 400°C. In both cases, the films had a stable tetragonal crystal structure. At the deposition temperature of 750°C, in a narrow thickness range SnO2 epitaxy was realized. In the growth experiments 80 • Biannual Report 2004/2005 from SnI4–O2 at temperatures 400–750°C, MgO(1 0 0), Pt/Si and TiO2/Si substrates were also used. In the first case, only a weak tendency of epitaxial growth was revealed. It was characterictic of the second and third case that the increase of the thickness was accompanied by an increase in the size of crystallites. On Pt/Si substrates, the growth of SnO2 films, in correlation with a high surface roughness, was exceptionally fast. At atomic layer deposition of gas-sensitive Cr2O3 films, CrO2Cl2, and CH3OH were chosen as precursors, and SiO2, Si(1 0 0), oxidized Si, and –Al2O3(0 1 2) as substrates. The films grew at a satisfactory rate when the temperature was relatively high (400–500°C). The growth resulted in crystalline films with the eskolaite structure. The growth on the sapphire substrates was epitaxial. Substitution of TiCl4 for CrO2Cl2 allowed also growing of TiO2 films in the abovementioned temperature range. Thus, a possible way of atomic layer deposition of Cr2O3–TiO2 mixtures for resistive gas sensors was paved. For the group including R. Jaaniso (leader), T. Avarmaa, A. Floren, M. Kodu, A. Kärkkänen, and I. Kärkkänen: A model was constructed for describing luminescence quenching in nonordered oxygen-sensitive solids, which takes into account the inhomogeneous distribution of the natural and oxygen-induced quenching rates. Model calculations were compared with the experimental quenching curves measured on PMMA films activated with Pd-tetraphenylporphyrin. A positive correlation between the natural and oxygen-induced quenching rates was found. It was shown that the photostability of Pd-tetraphenylporphyrin and Pd-tetrakis(pentafluorophenyl)porphyrin molecules in PMMA depends on the fact whether oxygen is present or not. A lower photostability in the presence of oxygen was explained by the influence of the singlet oxygen generated at the energy transfer. The study of the stability of kinetic parameters demonstrated that while physical Scientific Report • 81 ageing affects the effectiveness of energy transfer to oxygen through the change in its diffusion rate, the photochemical ageing affects the natural quenching time. A different character of photoproducts in the case of the two molecules in view was determined. Energy transfer in light emitting diode materials based on poly(vinylcarbasol) activated with Pd-tetraphenylporphyrin was studied. In luminescence kinetics, besides oxygen-induced quenching, concentration quenching was revealed, when the mass percent of the dye exceeded 1. The fact was explained by Förster energy transfer to free porphyrin. To describe the experimental data, a distribution function that takes into account the energy transfer to oxygen and immobile acceptors was created. All above results on porphyrinactivated luminescence bear a relation to oxygen sensors based on luminescence quenching. The sensor prototype was tested by determining the oxygen consumption of butterfly pupae. It was concluded from the measurements of the conductivity of single-wall nanotube films illuminated in various gases and vacuum that the decrease in the conductivity is due to oxygen photodesorption. The fast and reversible conductivity changes induced by polar molecules were associated with physisorption on the surface of nanotubes, while long-time photoprocesses (and the subsequent reverse processes) were attributed to the adsorption on nanotube defects or contact surfaces between the nanotubes. Comparison tests in dry and humid argon and oxygen showed that water that was photodesorbed and, subsequently, slowly adsorbed, is relatively strongly bonded to nanotube films. The tests also pointed to the interrelationship between oxygen and water sorption. It was shown that by pulsed laser deposition it is possible to grow Cr2O3–TiO2 films with a Ti content of 5–20 at.%. The films were deposited onto Si substrates in the rare oxygen atmosphere. The films crystallized when the O2 pressure exceeded 10–2 mbar and the temperature was higher than 400–450°C. The advantageous size (10–20 nm) of crystallites was achieved at temperatures 500–550°C. 82 • Biannual Report 2004/2005 In the case of 550°C films, the content of the crystal phase was estimated to be 80%. It was found that in the thickness range of 10–30 nm, the film crystallinity did not depend on the thickness. The crystallinity improved when the energy density of laser pulses was decreased. Further improvement was achieved by growing or annealing at temperatures above 600°C, but crystallites size exceeded then 100 nm. For the group including A. Lõhmus (leader), M. Järvekülg, I. Kink, M. Lobjakas, R. Lõhmus, M. Paalo, V. Reedo, K. Saal, J. Šulga, M. Timusk, T. Tätte, and S. Vlassov: Elaboration of a prototype nanotomograph based on scanning probe microscopy and pulsed laser etching was continued. An opportunity to observe the scanning and etching area by means of a digital optical microscope was added. The accuracy of horizontal movement was improved to be on the micrometer level. The device was used for studying the effect of laser irradiation on the surface of mica. It turned out that it was only in the case of the smallest irradiance used that the removal of material was sufficiently homogeneous. It was shown that the tip radius of the transparent and electrically conducting SnO2 probes prepared by sol–gel technique depends on the fiber drawing velocity, humidity of the atmosphere, and viscosity of the source material. The radius could be minimized to 15–25 nm. The probes allowed one to collect the tunnel current generated light and get surface images with a nanoresolution. The properties of the nanostructured copper, obtained by the method of strong plastic deformation, were studied after its mechanical and thermal processing. A connection between size of the granules (40–120 nm) and mechanical strength of the material was revealed. With the increase of size, mechanical strength decreased and yielding increased. Methods of preparation of aminofunctional SiO2 films by sol–gel technique were elaborated. The methods allow one to vary the surface Scientific Report • 83 concentration of amino groups and the degree of film hydrophility. Usability of the films as substrates for DNA microarray analysis was experimentally proved. In further investigations, the optimal content of 3-aminopropyltrimetoksysilan in the films, necessary for binding DNA, was determined. The surface concentration of amino groups was assessed. Next, sol–gel syntheses of HfO2 in which hafnium tetrabutoxide dissolved in butanol was polymerized by addition of H2O in the presence of an HCl catalyst will be described. By sol–gel technique, pure HfO2 films and the films doped with rare-earth metal ions (Sm3+, Tb3+, Eu3+) were prepared. Dip coating was successively carried out from prepolymerized 5% hafnium polymer solution in hexane. For doping, SmCl3, TbCl3 or EuCl3 was added to the water necessary for starting the polymerization. As a result, films with an even distribution of impurities were created. Compared to the ion implantation, the procedure is simpler and the scale of the applicable impurities larger. The surface roughness of the films was in the range of nanometers. Methods for preparation of HfO2 fibers with a diameter of 10–50 µm were elaborated. It was shown that sol is most suitable for fiber drawing if the concentration of the catalyst used is larger than 0.2%. The tensile strength of the fibers was measured to be 170 MPa. It was shown that by processing of hafnium polymer, microscopic tubes or rods with dimensions about 1 u 100 µm can be precipitated. The objects were oxidized at 600°C. The final products have a potential for the use as probes in atomic force microscopes and nearfield scanning optical microscopes, catalysts with a large specific surface area and sources for preparation of carbides. Methods for preparation of microstructured HfO2 surfaces from prepolymerized hafniumtetrabutoxide were worked out. The height of the surface structures (pyramids) was measured to be 2–3 mm and the width 3–10 cm. These surfaces can be used in detectors of energetic particles. 84 • Biannual Report 2004/2005 For the group including P. Adamson and A. Kasikov: Theoretical studies of light reflection from media consisting of ultrathin dielectric biaxially anisotropic homogeneous films on massive absorbing or transparent isotropic and homogeneous substrates were carried out. It was shown that if the film thickness d is considerably smaller than the light wavelength and the substrate is transparent, the contribution of each film to the reflectance is a nonadditive second-order infinetisimal. In the case of absorbing substrates, the light intensity change caused by each film is proportional to d/ . The ellipsometry theory was developed for a system of several arbitrary anisotropic nanolayers. Approximation equations for differential ellipsometric angles were derived. It was shown that in the case considered, in addition to the traditional ellipsometric angles the socalled generalized ellipsometric angles can be used. Opportunities of applying the approximation for the determination of parameters of anisotropic stratified nanostructures from differential ellipsometric measurements were analyzed. Various models were used for determining the optical parameters of depth-inhomogeneous vacuum evaporated ZrO2 films from transmission spectra. Among envelope models, a model by Swanepoel applied with a correction obtained in the region of smallest dispersion, turned out to be the best. It was shown that when describing multiparameter inhomogeneity, the two-layer model has advantages in comparison with the linear one. Transmission spectra of atomic layer deposited TiO2 films were analyzed using Lorentz dispersion and the two-layer model. It turned out that the deposition parameters markedly influence the depth dependence of the refractive index. The dependence was demonstrated to be assessable even if the interference fringes are weakly developed. Scientific Report • 85 For the group including P. Konsin and B. Sorkin: The free energy of oxide perovskites (BaTiO3, KNbO3, etc.) was calculated taking into account the electron–lattice hybridization between the valence and conduction bands and the dependence on the electron wave vector. The dependence of the permittivity of quantum paraelectrics (SrTiO3, KTaO3, CaTiO3) on the electric field was investigated. Its gigantic increase in SrTi16O3 when weak electric fields and ultraviolet illumination are applied was predicted. By analogy with the theory of superconductivity in graphite intercalation compounds, a model for the superconductivity in MgB2 was proposed with all actual intraband and interband electron–lattice and Coulomb interactions taken into account. The specific heat and superconducting gaps were estimated. On the basis of a two-component model, the superconductivity transition temperature in function of the concentration of holes p in La2–xSrxCuO4 films was calculated. The dependences of the Ginzburg–Landau coherence length and the upper critical magnetic field on p for cuprates were shown to have a minimum and maximum, respectively. Compiled by Arnold Rosental 86 • Biannual Report 2004/2005 Biophysical elementary processes and their dynamics There have been three main research subjects under this project we were focused on in the period of 2004–2005. Mechanisms of Spectral Fine-Tuning in Bacterial Photosynthetic Antennas The ways photosynthetic organisms, plants, algae, and bacteria, harvest solar energy and adjust efficiently to environmental extremes has been of considerable interest over a long time already. This steady interest is partly fueled by the hope of finding new biomimetic principles applicable in synthetic molecular devices. The modern history of solar energy transfer and trapping in photosynthesis can perhaps be traced back to the work of Franck and Teller almost 70 years ago. Subsequent studies have established a concept of an energetic funnel formed in photosynthetic membranes by the specialized pigment-protein units that carry self-explanatory names of antenna and reaction center complexes. According to this concept the arrangement of the electronic transition energies of the pigments is generally ordered, so that the pigments closer to the reaction center sink absorb progressively more red-shifted light from the solar spectrum. The photosynthetic bacteria match best this simplified view of the funneling photosynthetic unit. In all species of the purple photosynthetic bacteria the reaction center is encircled by a core or LH1 antenna complex. In many of them also a network of peripheral LH2 antenna complexes exists next to LH1. If to add that high-resolution crystal structures are present for both the reaction center and LH2 antenna complexes, it becomes understandable why bacterial and not plant species have been distinguished as the main test ground for detailed understanding of the factors governing the spectral properties of antennas and reaction centers. Scientific Report • 87 Closely packed but non-covalently bound molecules constitute the photoactive part of most photosynthetic complexes. The protein frame is believed to provide a general structural support preventing the pigment aggregates falling apart, but also to affect the electronic properties of the pigments by supplying them individual binding sites. Previous investigations have demonstrated a great role of pigment-pigment and pigment-protein interactions in modification of spectral properties of the bacterial antennas. The pigment-protein interactions are the source of the so-called solvent shift of transition frequencies of the pigments. Just like in common molecular solutions, bonding to the surroundings can be broadly divided to non-specific van der Waals couplings and to specific ones such as hydrogen bonds. The various interactions between the pigment molecules that lead to collective excitations delocalized over many molecular units may all be classified as excitonic. Spectral manifestations of the solvent shift interactions in LH1 and LH2 antenna complexes are numerous. The excitonic effects, however, are much less firmly established. This lack of knowledge is partly due to high spatial symmetry and partly because of inevitable disorder (static as well as dynamic) of the antenna structures. The LH1 and LH2 complexes possess similar circular arrangement of tightly packed (the inter-pigment distance comparable to the molecular size of ~0.9 nm) bacteriochlorophyll a (Bchl) molecules as the main photoactive pigments. The transition dipole moments for the lowest-energy Qy electronic transitions of the molecules in both structures rest almost in the plane of the ring. The quantum mechanics then rules that only two degenerate exciton states (the second and third lowest) out of the total 32 (LH1) or 18 (LH2) states reveal themselves in the linear absorption spectrum. The rest of the states are dark, i.e. not accessible from the ground-state absorption. While the variations of the surrounding matrix to some extent mitigate this symmetry-controlled selection, they equally confuse the assessment of genuine characteristics of the exciton. 88 • Biannual Report 2004/2005 Using polarized fluorescence excitation spectroscopy, we succeeded in determining the bandwidth of the exciton manifold in the LH1 and LH2 complexes purified from the purple bacterium Rhodobacter sphaeroides. The model simulations based on experimental crystal structures also allowed the weak high-energy exciton band tail to be revealed for the first time. Still the relationship of the solvent shift and exciton coupling components in spectral fine-tuning remained elusive. To work out this problem, advantage is taken from the fact that some strains of purple bacteria develop special variant of the peripheral antenna complexes named LH3, spectroscopically distinct from the regular LH2, when growing under stressed conditions, e.g., low light intensity or low temperature. In the LH3 complex from Rhodopseudomonas acidophila strain 7750 the lowest-energy absorption band maximum is at 820 nm, almost 50 nm (or 700 cm–1 in energy) blue-shifted with respect to its position in the lowtemperature spectrum of LH2. We determined that almost no change of the exciton couplings accompanied this shift (exciton bandwidth in LH3 is less than 10% narrower compared with that in LH2). This implies that the blue shift should be mainly attributed to the changes in bonding patterns between the coupled Bchl molecules and the protein. A comparison of the high-resolution crystallographic structures of the antennas, which clearly demonstrates changes in the hydrogen bond network, supports this interpretation. This way the important roles that the protein and the neighboring pigments separately play in modulation the characteristics of the lightharvesting systems have been revealed for the first time. We hope that these studies may prove useful for understanding nanoscale molecular assemblies as well as for designing more efficient light-harvesting devices. [19, 67, 68, 79, 205, 218] Scientific Report • 89 Pressure-Tuning Spectroscopy as a Tool for Investigations of Intermolecular Interactions In natural conditions the chlorophylls and bacteriochlorophylls form readily complexes with a variety of other molecules, including solvents. A traditional approach to study the interactions of solute electronic surfaces with the solvent is by measuring the shifts and shapes of optical spectra employing different solvents. However, this method is subject to serious shortcomings due to the discontinuous change of bulk physical properties and microscopic chemical composition of the solute environment when varying the solvent. In contrast, by applying external hydrostatic pressures, continuous tuning of solution properties over considerable range can be achieved. When combined with optical spectroscopy, this technique provides a very promising barochromic alternative for the solvation studies. The conventional solvation models operating with macroscopic experimental parameters, such as the dielectric constant of the solvent, generally fail in explaining the electronic level shifts and transition energies, least the geometry changes of the molecules, due to variations in the coordination number occurring during the solvation. The atomic level approaches based on quantum chemistry are therefore necessary for calculations of these effects. Due to the size of the systems considered (140 atoms even without any solvent) the quantum chemical methods of higher accuracy (ab initio at Hartree Fock (HF), post-HF or DFT level with reasonably large basis sets) are unfortunately not applicable, especially for modeling solvent effects as a function of pressure. While the spectra of different chlorophylls have been calculated at various levels of sophistication for unsolvated molecules and molecules in complex with a few solvent molecules, to our knowledge, no previous modeling of pressure dependent solvation effects has been done. We have performed the atomic level simulations of the hydrostatic pressure effects on the absorption spectra of chlorophyll a and bacteriochlorophyll a in diethyl ether solution. The methodology 90 • Biannual Report 2004/2005 combining CHARMm, PM3 and ZINDO/CI methods yields results in good agreement with the experimentally observed spectra, explaining the behaviour of the barochromic shifts of the Qy, Qx and Soret bands up to 9 kbar. The simulations also reveal important aspects of solvation effects and their pressure dependence. Close agreement with the experimental data shows the potential of the method and encourages for future studies in more complex environments, including native protein surroundings of photosynthetic complexes, our ultimate goal. [16, 21, 216] Photosynthetic O2 evolution from leaves at wavelengths beyond 680 nm The quantum yield of photosynthesis, calculated per absorbed light quanta, drops at the red end of the absorption spectrum of leaves and green algae. This drop can be compensated with the help of an accompanying illumination at shorter wavelengths, a phenomenon known as Emerson enhancement effect. The reason of the red drop is the unequal distribution of excitations between the two photosystems, photosystem II (PSII) and photosystem I (PSI), which operate as a tandem. For stable operation with high efficiency, electron transport rates through the two photosystems must be closely equal that requires similar excitation rates. The antenna system of PSI contains a number of so-called far-red chlorophylls (Chls), which absorb at wavelengths beyond 700 nm. As a result, the far-red light is mainly absorbed by PSI. Since the rate of electron donation to PSI is determined by PSII, which is insufficiently excited, it strictly limits the overall quantum yield of photosynthesis at the far-red end of the Chl absorption spectrum. Occurrence of similar far-red Chls in the PSII antenna is not recognized, though O2 evolution at wavelengths beyond 700 nm has been reported and the optical cross-section of the responsible Chls has been calculated. Since this cross-section was very small at 723 nm, it was assumed to be a tail of the Chl a absorption. Scientific Report • 91 Though the red drop has frequently been discussed in earlier photosynthesis research, the extension of oxygen evolution to the farred end of the spectrum was seldom emphasized. After the zirconiumbased oxygen analyzer was taken into the armament by photosynthesis researchers, precise measurements of O2 evolution became possible from the leaves. Applying the zirconium analyzer for the O2 evolution measurements and a tunable laser for illuminating the leaves, we were revisiting this classical problem. A distinctive aspect of our approach was that the leaves attached to the growing plant were used in order to avoid changes that may occur upon disruption of the leafs or cells. This way the light-activated O2 evolution from the sunflower leaves at extraordinarily far-red wavelengths up to 780 nm were measured. The quantum yield of O2 evolution has a local peak at 745 nm almost reaching 20% of the maximum yield of 0.39 at 650-nm excitation. The similarity of the result for the sunflower and bean proves that both the extreme long-wavelength oxygen evolution and the local quantum yield maximum are general properties of the plants. The observations were discussed in terms of as yet undisclosed far-red forms of the chlorophyll in the photosystem II antenna, reversed (uphill) spillover of excitations from PS I antenna to the PS II antenna, as well as absorption from the thermally populated vibrational sub-levels of photsystem II chlorophylls in the ground electronic state. [194, 195] Compiled by Arvi Freiberg 92 • Biannual Report 2004/2005 Environmental radioactivity and radiation dose in Estonia Collection of soil samples and their gammaspectrometric analysis was continued in order to determine the depth profiles of man-made and natural radionuclide concentrations and the radon emanation coefficients. Besides the Ra-rich areas in NE Estonia, the samples were collected also from other regions of Estonia, characterized by a medium Ra-content. In collaboration with the Kiirguskeskus (Radiation Centre) the analysis of the aerosol filter samples was continued, yielding the data of 210Pb and 7Be content in air and its temporal variation in three Estonian sites (Harku, Tõravere, Narva-Jõesuu) in 2001–2005. The samples have been collected with the high-volume air samplers. The radionuclide concentrations in the soil and aerosol filter samples were determined by the low-background gammaspectrometry, using two HPGe spectrometres. The purchase of a sensitive HPGe spectrometer equipped with a planar detector GPD-50400 (BSI, Latvia) was financed by an Estonian-Danish joint radiation protection project and it was implemented in 2004. This instrument replaces the former low-efficiency planar detector spectrometer. In 2005 a new basic instrument, a contemporary portable HPGe gammaspectrometer InSpector 2000 (Canberra, USA) was implemented and the gamma spectrum analysis software GENIE2000 was mastered (K. Realo). 1. Radionuclides in soil a) 210Pb. Characteristic for the soil in NE Estonia is the variation of U/Ra rich regions and precipitation of radionuclide containing fly ash, produced by the long-term exploitation of local power stations. The formerly established 238U dilution (reaching in some locations 57% of the 226Ra concentration and a remarkable Pb deficite relative to the same radionuclide in the highly Ra-contaminated regions causes some difficulties as to unambigous interpretation and Scientific Report • 93 modelling of 210Pb depth profiles. Therefore, the depth profiles were sampled in two groups: from the areas with possibly low Ra concentration in vicinity of the big power stations, and far from them (> 10 km). The obtained 226Ra activity concentrations varied in the interval 14–35 Bq kg–1 and the corresponding Rn emanation coefficients fell into the limits 0.1–0.6. The 1-D diffusion model was improved to separate the supported and unsupported 210Pb fractions in the depth profile and to improve the precision of the corresponding migration parameters. About 67% of the Pb unsupported fraction is found in the surface layer of 0–10 cm. In addition to the diffusion model, a 4-compartment transport model was introduced to describe the time-dependent migration of 210Pb from the soil surface to deeper strata. The transfer rates in the set of differential equations of the model have been found, fitting by the Scientist 2.01 software the partial activities determined from the analysis of the soil samples to the solutions of the model. The mean atmospheric concentration of 210Pb in air of Narva-Jõesuu (located ca 20 km from the power stations and the Ra-rich regions) was used as an input parameter. The arithmetical mean concentration was 0.453 mBqm–3 and geom. mean 0.387 mBq m–3. For both models the transfer parameters were determined for both depth profile groups. In general, the found transfer rates for two soil groups are approximately equal. Thus, the migration in soil follows nearly the same kinetics and only the the mean deposition fluxes differ. The average downward migration velocity of 210Pb into deep layers is ~0.27–0.30 cm a–1. In the region, less contaminated by flyash, the 210Pb mean atmospheric deposition flux is 164 Bqm–2a–1 and the mean deposition velocity equals to 12 mms–1. At the same time, for the second group a higher deposition flux of 321 Bqm–2a–1 was obtained. This can point to the enhanced deposition velocity, or, most probably, to an enhanced 210Pb content in air near the power stations. The observed high deposition fluxes (and deposition velocities) support an 94 • Biannual Report 2004/2005 assumption about industrially enhanced 210Pb inventory in soil at sites near the power plants (K. Realo, E. Realo, R. Koch). b) 134Cs ja 137Cs. Our studies (1991–1993) of the activity concentration in soil depth profiles, induced by the Chernobyl accident, yielded a simple monoexponential distribution with the relaxation lengths in the region of 1.5..3 cm as a sufficiently good approximation. The depth profiles, obtained in 1998–2003 by 2–3 cm sections down to the depths of 20 cm, were analysed. The Chernobyl contribution in the 137Cs content was computed from the 134 Cs analyses. The depth profile analysis confirmed the migration of 137 Cs into the deeper soil layers: the dependence of concentration on depth is not exponential any more and it displays below- surface maxima. It turns out that the general form of the 1D diffusionadvection migration in the case of a short term deposition (see, eg [P. Bossew, G. Kirchner. J. Environm. Radioactivity (2004) 73, 127–150]) can be successfully approximated by a simple normal or log-normal model. Using the latter, the determined 137Cs concentrations in depth profiles were fitted and the time-dependent parameters, xc and w, of the log-normal model were obtained. These parameters demonstrate approximately linear time dependences. The internationally accepted model RP72 gives the same result, except the short time interval immediately after deposition. The compartmental modelling was also exploited to determine the values of the advection rate v and the diffusion coefficient D, which can be compared to the parameters of the 1D model. (M. Lust, K. Realo, E. Realo). 2. 7Be and 210Pb in air 7 Be is a cosmogenic radionuclide, produced by cosmic radiation induced nuclear reactions involving oxygen and nitrogen atoms in stratosphere. Its migration into the near-surface air is due to the descending air masses. 210Pb is a long lifetime daughter product of 222 Rn, The released radon atoms from soil particles are transported by advection and diffusion through the pores and a fraction of them is Scientific Report • 95 released into the atmosphere. Radon nuclei undergo a number of decays to produce 210Pb, which migrates with air masses, is spread by turbulences, etc. Simultaneous study of the 7Be and 210Pb concentrations gives significant information on the transfer of radionuclides in the environment, as well as on the dynamics of physical processes in the atmosphere (7Be is formed in the stratosphere and 210Pb in the troposphere, different sedimentation processes, etc.). All the above features have made these studies attractive for applications in atmospheric transport and removal processes, oceanography and sedimentation, geophysical dating. It should be underlined that their content in air depends significally on the regional and local weather. The three high-volume filter samplers are situated rather appropriately in Estonia. Ca 650 air filter samples have been analysed. Up to now we have data for the years 2001–2005: a) weekly 210Pb and 7Be mean concentrations in air and temporal variations in three locations (Harku, Tõravere, Narva-Jõesuu); b) meteodata for the same locations; c) the data on the area dose rates. Establishing of the corresponding correlations/regressions is started and being continued. The first conclusions, needed for development of a general model of the transfer of these nuclides in the Estonian environment, are the following: – The air concentrations near the sea (Harku and Narva-Jõesuu) are smaller than in the inland (Tõravere): Rn does not emanate from the marine environment; for 7Be we found a significant negative correlation with the air humidity. – The ratio of 7Be and 210Pb concentrations varies widely from 0.6 to 16.6 in all sampling sites. It reaches maxima in summer as a result of thermal convection upon 7Be transport, together with the descending air masses from the higher atmospheric layers. In 96 • Biannual Report 2004/2005 winter, the ratio is minimal, while 210Pb has an enhancement trend. – The air temperature and air pressure have the greatest effect upon the 210Pb concentration. The magnitude of air pressure 3–5 days before the sampling interval influences its concentration more than the value during sampling. The wind speed diminishes the 210 Pb concentration mostly. 7 – Be content correlates significantly with air humidity and air temperature. – The regional weekly mean dose rates at the sampling sites practically do not correlate with neither 7Be nor 210Pb content in air. Performing of multivariant regressions of the data is under way. As part of the weather parameters are correlated, the Pearson correlations do not yield reliable results due to their collinearity. 3. Radionuclides in lichens and peat Peliminary results were obtained, investigating contents of 137Cs and natural radionuclides in lichens. The radionuclide content in the objects, known as significant indicators, were compared with the contents in soil samples, collected in the vicinity. The transfer factors “soil-lichen” and “air-lichen” were established. This new research subarea (MSc thesis of L. Aarik) explores the possibility of using lichens for determination of environmental radionuclide activity concentrations and finding the transfer factors between various compartments of the environment. It is a novel trend in the field, aimed at the elucidation of bioindicators for radionuclides in our environment and at the finding correlations of 137Cs, 7Be and 210Pb contents in lichens, air and soil. In the work by L. Aarik, the radionuclide contents in the samples, collected in the vicinity of Tõravere and Tartu, along with the related transfer factors, were Scientific Report • 97 determined. Collection of samples from a wider area and their analysis is in progress (L. Aarik, M. Kiisk). 4. Quality assurance in gammaspectrometric analyses, modelling Elaboration and testing of the methods of preparation of lichen and peat samples and analyse of them of radionuclides. The work is underway, preliminary results are promising (M. Kiisk, L. Aarik). Detection limits of low-energy low-intensity gamma-emitting natural radionuclides, such as 230Th and 238U, by gammaspectrometric analysis have been determined. The software for gammaspectrometric analysis of U and Pu samples (obtained via project JRC ITU, Karlsruhe) was tested (M. Kiisk, K. Isakar, K. Realo, T. Sisask). The modelling software RESRAD for long-term radionuclide migration was modified to take into account the inhomogeneity of the radioactive wastes. It was applied to assess the radiological impact of the interim depository of radioactive wastes in Paldiski for the time spans up to 10000 years in the near-field and far-field exposure pathways (in collaboration with the ALARA, Ltd.). Different versions to dispose small sealed radiation sources mixed with large amounts of conditioned low-activity wastes and the corresponding exposure pathways have been analysed. The results might be useful to find the economical disposal options of high-activity sealed sources and the conditions to be followed in designing containers/ waste packages (E. Realo). Our participation in the intercomparison excercises of the Nordic and the Baltic states NKS 2002/3 and RISOE 2004 (2004/5) gave good results. The overall result in the 2002/3 excersise (published in 2004): the deviations were insignificant in the cases of all radionuclides. From 17 participating labs, we were among these 6 labs, which passed the exercise. The results confirm the high analysis quality and the advanced qualification of our analysts. In a number of locations in Estonia the ground water contains high levels of radium. This fact gives rise to health problems and 98 • Biannual Report 2004/2005 makes the adequate investigations actual. We elaborated the analysis method and started the gammaspectrometric analysis of Ra in drinking water and the dose assessment of internal exposures to the population (supported by the contract with the Health Protection Service of the Ministry of Social affairs). In collaboration with the Central Laboratory of Health Protection, we reached acceptable results in the intercomparison exercise on the radionuclide analysis in water samples, arranged in 2004 by the Ministry of Social affairs (M. Kiisk, K. Realo, E. Realo). The gamma radiation transfer software GEANT4 (CERN) was applied for the Monte Carlo modelling of detailed interactions of low-intensity low-energy gamma-rays for nuclides 210Pb, 230Th and 238 U in the complex source-detector geometry (K. Isakar). A simplified model has been elaborated to compute the correction factors, taking simultaneously into account different self-absorption and sample height. The corrections were exact down to 1–2 %. The model based on exact Monte Carlo modellings (K. Realo, E. Realo, K. Isakar). 5. The polariton theory in the gamma-resonant spectroscopy The propagation of the Mössbauer radiation was analyzed in terms of the collective nuclear excitations, created in a resonant medium due to multiple coherent scattering. The cooperative effects were investigated in two different situations: 1) propagation of resonant synchrotron radiation (SR) in the case of splitted Mössbauer levels and 2) creation or decay of a stationary beam of nuclear polaritons (NP). 1. It has been shown that the primary pulse of SR, penetrating the sample, creates a collective nuclear excitation in it. If the hyperfine interaction is strong (level splitting exceeds the width of the broadened absorption lines), the initial collective state is decomposed very rapidly, due to dephasing, and independent nuclear excitons (NE) arise instead of it. The number of NE (freely oscillating ensemble of nuclear multipoles) equals to n (the number of different Scientific Report • 99 Mössbauer transitions) and each NE is characterized by its frequency and initial phase. Interference of the secondary gamma-quanta, emitted by different NE, causes pronounced quantum beats of the transmitted radiation intensity. However, this structure is modulated by the dynamical (polariton) beating phenomenon. In the case of a moderate or weak splitting, the initial collective nuclear excitation decays as a single NE, creating NP in the sample. These NP are characterized by the same group velocity and different frequencies. The intereference of NP causes the beating of the transmitted radiation, beating parameters determined by the NP characteristics. During the process, the number of the interfering polaritons changes from 2 to n+1. 2. In a resonant medium, a beam of Mössbauer radiation is converted into a beam of NP (mobile nuclear excitations). We have shown, that the photon-polariton conversion takes place in a finite layer of the sample during a finite time interval, the corresponding parameters depending on the radiation frequency. Furthermore, only part of the coherent secondary radiation, created by the ensemble of the excited nuclei, is represented by the polariton wave. The second component, the screening field, prevents the primary beam from penetrating into the bulk of the sample (quantum theory analog of the Ewald-Oseen theorem in the classical optics) and is the reason of significant effects in the rapid (non-adiabatic) transition processes. If the primary beam is rapidly switched off, the screening field may cause a short increase of the transmitted radiation. If the radiation source is switched on, the screening field, as the most dynamical component, determines the length of the precursor pulse. In both cases, the further evolution can be described as the slow movement of the polariton wave-front across the sample. Thereby the shape of the front does not depend on the primary beam. These effects have been observed in the Mössbauer time-domain experiments, the results being in the agreement with the theory, developed in our institute. Compiled by Enn Realo and Mati Haas 100 • Biannual Report 2004/2005 Theory of Fundamental Structure of Matter The theoretical physics belongs to the traditional research fields of the Institute of Physics. The topic of research project is rather broad; it includes the theory of condensed matter, optics and spectroscopy, the high-energy physics and general relativity. A characteristic feature of the last 10 years is the essential increase of joint research with scientists from abroad, especially from Europe and United States; approximately half of papers are written in international collaboration. The teaching of theoretical physics and supervision of students and post-graduates in theoretical physics is also one of main goals of the project. Theory of elementary particles and gravitation Braneworld cosmology One of the main challenges for contemporary theoretical cosmology is to explain the physical nature of dark energy, which may account for up to two thirds of the energy density of the Universe. A possible explanation can be found in the framework of the braneworld cosmology, where our Universe is one of two hypersurfaces embedded into a 5-dimensional bulk spacetime and a scalar radion field measures the proper distance between the branes. Mathematically, the corresponding theory is a scalar-tensor cosmology with a nonconstant coupling function. Our investigations demonstrate that the two-brane cosmological model in the first approximation of gradient expansion written by Kanno and Soda [Phys. Rev. D66: 083506 (2002)] as a scalartensor theory with a specific coupling function can be understood as describing two Friedmann-Robertson-Walker type cosmologies on two branes. The only contact between the branes is established by the constraint equation which determines an integration constant in the first integral of the equation for the Hubble parameter of our Universe in terms of an integration constant in the solution of the Scientific Report • 101 equation for the second (hidden) brane. The value of the integration constant can be interpreted as the value of the energy density of the dark radiation at a fixed initial moment t0. Solutions for some special cosmological models are found (solution with a constant dilaton field, radiation dominated Universe with cosmological constant etc.). The influence of the asymptotic nontrivial scalar field on gravitational experiments in the Solar system encoded in the parametrized postNewtonian (PPN) parameters is estimated. Anomalous gauge boson self-couplings One method to test possible new physics (NP) beyond the Standard Model (SM) is based on observation of small departures from the SM predictions in processes, where the external particles are ordinary SM ones, and NP effects can arise only from the anomalous (nonstandard) couplings. Among the most promising processes to which anomalous couplings could contribute, is the process e+e–oZJ Through this process the possible existence of anomalous couplings between three neutral gauge bosons (ZZJ, ZJ ) can be tested. By exploiting a method based on the use of general relativistic spin–1 density matrix used by us earlier [I. Ots et. al., Nucl. Phys. B 588 (2000), 90], we have evaluated and analysed the contributions from possible anomalous ZZJ and ZJJcouplings to the spin orientation of the Z boson in e+e–oZJ with longitudinally polarized (LP) and transversely polarised (TP) initial beams. The main features of the LP and TP contributions to the Z boson spin polarization vector and the alignment tensor have been presented and their roles in disentangling different sets of couplings (SM, ZZJ, ZJJ) have been clarified. It has been shown that by using LP initial beams one can substantially enhance the sensitivities to one or other couplings. However, LP does not enable measurements of the parts of couplings which are, at least in principle, inaccessible with unpolarised beams. Contrary to LP, TP can enable such measurements. In the case of anomalous couplings, simultaneously TP initial beams provide the theory with extra 102 • Biannual Report 2004/2005 directions due to which the Z boson polarization vector obtains additional, out-of-reaction-plain components and new alignment axes are added to the alignment tensor. Since the orientation of the Z boson is transferred to the angular distribution of its lepton decay products, one can put limits to the anomalous couplings by probing the Z boson spin polarization and alignment through the measurement of the shape of Z boson lepton decay spectrum. For details see a special article on pp 26–29. Theory of solid state, optics and spectroscopy In the field of condensed matter, optics and spectroscopy the research is performed in close collaboration with the experimental studies in the institute. In years 2004–2005 main results were obtained in the theory of vibronic transitions, nonlinear lattice dynamics, quantum and singular optics, in the study of strongly correlated systems, and phase transitions in crystals. Nonlinear dynamics, optics and spectroscopy Recent years studies have shown that strongly localized vibrational excitations can exist in perfect nonlinear lattices. The frequency of such a vibration depends on its amplitude and lies outside the phonon spectrum. Such vibrations are called intrinsic localized modes (ILMs), to emphasize their similarity in appearance to defect impurity modes, or discrete breathers or discrete solitons to make a connection to solitons in continuous systems. The discovery of this intrinsic dynamical inhomogeneity should lead to other new features. In our investigations we have found that the appearance of an ILM in the lattice changes the local phonon dynamics. As a result of this back reaction on the phonons the ILM induces appearance of linear local modes (LLMs) outside the phonon spectrum. A theory is developed for describing this effect in a monatomic chain with hard quartic anharmonicity. To verify it, molecular dynamics simulations of vibra- Scientific Report • 103 tions under strong local excitation have been carried through with high precision. The numerical results fully confirm the prediction. A general theory of the spin-dependent and spin-independent longitudinal and transverse shifts at reflection of the light beam carrying the orbital angular momentum is developed. In the case when the incident beam is paraxial and s- or p-polarized, the following results have been obtained. The closed formula has been deduced which describes the position of the center of gravity of the reflected beam on the whole output plane, the position does not depend upon of the dimension of the cross-section of the incident beam. A method of the experimental definition of the transverse shifts of such beams is proposed; the method is based on the difference of the transverse shifts of the p- and s-polarized beams through a crosscorrelation function. It is shown that the change of the intrinsic normal component of the angular momentum of the beam at reflection must be accompanied by appearance the extrinsic one. A theory of the dynamical Casimir effect,− the quantum emission of a dielectric with periodically changing in time refractive index n has been developed. The changes of n in time cause analogous changes in time of the optical length. It is demonstrated that a resonant enhancement of the quantum emission takes place if the maximum velocity of the changing in time of the length mentioned approaches a critical value Vcr. Our calculation gives Vcr ≈ 3c. Basing on the ideas of the Feynman path integrals, a new method of calculation of optical spectra of impurity centres in crystals in the case of an arbitrary quadratic vibronic coupling is proposed. In this method, to calculate the Fourier transform of the spectrum the time evolution of the final state of the transition is divided into a large number N of time steps. Taking into account that the time evolution between the steps is classical, the calculation of the Fourier transform is reduced to the computation of the determinant of the N × N matrix and its reciprocal matrix. The matrix elements are given by the 104 • Biannual Report 2004/2005 pair correlation functions of the contributing configurational coordinates. The method is verified for a system with two mixing modes. A theory of vibronic spectra in the centres with strongly reduced local elastic constants in the excited state has been developed. The theory exploits the existence of a small parameter in this case the ratio of the mean frequencies of vibrations in the final and initial states. In this case the long-wave part of the phonon sideband of the spectrum is strongly enhanced. The spectral line has strongly asymmetric envelope with a peak at the frequency of the zero-phonon transition; its shape is modulated. The origin of the modulation lies in the effect known as the Airy oscillations. The dependence of the spontaneous emission rate (SER) of a single impurity molecule on the orientation of the dipole moment with respect to the principal axes of the dielectric tensor of the host crystal has been calculated for seven biaxial host crystals (anthracene, chrysene, diphenyl, fluorine, naphthalene, phenanthrene, terphenyl). The differences in the SER values in the same host crystal may attain 34%. Strongly correlated systems, high-Tc superconductivity, phase transitions A model of a cuprate superconductors based on the electron spectrum steaming from the doping of holes with the interband pairing channel has been developed. This model reproduces the behavior of basic superconducting characteristics in qualitative agreement with experiment in the whole doping scale. E.g. the calculated coherence length depends non-monotonously on the hole concentration C in agreement with measurements. The dependence of the supercarrier density and the critical magnetic fields on C follows the transition temperature. In the under-doped case the effective mass of the supercarriers slowly diminishes with C. Scientific Report • 105 Basing on results obtained in the t-J model of Cu-O planes and Mori’s projection operator formalism, the peak in neutron scattering experiments at the antiferromagnetic wave vector in yttrium cuprates has been interpreted as excitations of localized Cu spins. The highfrequency incommensurability detected in lanthanum and yttrium cuprates is connected with the dispersion of these excitations, while the low-frequency incommensurability arises due to a dip in the spinexcitation damping at the antiferromagnetic wave vector. For moderate doping the dip stems from the weakness of the interaction between the spin excitations and holes near hot spots. The diagram technique for the one-band Hubbard model is developed for the case of moderate to strong Hubbard repulsion. The expansion in powers of the hopping constant is expressed in terms of site cumulants of electron creation and annihilation operators. For Green's function an equation of the Larkin type has been derived and solved in a one-loop approximation for the case of two dimensions and nearest-neighbor hopping. At half-filling the obtained four-band structure of the spectrum is close to that observed in Monte Carlo calculations. With decreasing electron concentration a new narrow band of the spin-polaron type arises in the energy spectrum near the Fermi level. The anomalous enhancement of the dielectric constant by both the UV and DC electric field has been found in quantum paraelectrics of perovskite oxide types. A gigantic increase of the dielectric constant in UV light and DC electric fields is connected with the renormalization of effective charge by the soft mode. The timedependent Ginzburg-Landau equations in cuprates have been derived for the case of two-order parameters and the pseudogap. The relaxation times of the order parameters and pseudogap have been found. n The coupling of F1u vibrations with the electronic states of BO6 cluster in ABO3 ferroelectric-oxides leads to the dynamical covalency hybridization of B(Ti,Ta,Nb) and oxygen electronic states. The 106 • Biannual Report 2004/2005 n adiabatical potential for BO6 (n=6,8) has been obtained. The offcenter displacement of B ions has been calculated. Compiled by Piret Kuusk, Ilmar Ots, and Vladimir Hizhnyakov Laser physics and laser-optical technologies Research and development within framework of this theme carries on the Institute’s traditionally strong studies in the field of low temperature spectroscopy, wave optics, nonlinear and laser spectroscopy, photophysics and photochemistry of laser active media as well as development of associated experimental equipment and technologies in cooperation with local small high-tech companies. Some main results on localization of photon wavepackets had been introduced already in Section “Research Highlights” in the papers by P. Saari and V. Peet. Luminescence of Ȗ-radiation-induced defects in Į-quartz crystals Optical transitions of point defects play a crucial role in applications of silicon dioxide (SiO2). The transitions associated with -radiationinduced defects in crystalline -quartz have been investigated by photoluminescence methods. These studies have been carried out in collaboration with researchers from Latvia and Italy. Synchrotron radiation and steady-state light have been used for the excitation of luminescence. Two characteristic emission bands have been established as a result of 10 MGy -dose: an ultraviolet band at 4.9 eV and a blue band at 2.7 eV, both being excitable in the range of the induced absorption band at 7.6 eV. Both these emissions decay in the time scale of few ns under pulsed excitation, while the blue band can also be observed in slow recombination process, and it afterglows in about 100 s at the end of steady-state excitation. [11] Scientific Report • 107 Electron transport properties of low-dimensional systems Miniaturization of components is a trend in microelectronics, which is closely related to the effects of quantum interference and the phenomena of decoherence of conduction electrons. In this context studying the electron transport properties of the compounds Nb4.77Te4 and Ta1.2Nb3.4Te4 with quasi-one-dimensional crystal structure is certainly of interest. These studies have been performed using monocrystalline samples of 3–5 mm length and 0.005–0.05 mm2 cross-section. Measurements involved temperature range from 0.3 to 270 K and the magnetic fields up to 11 T. Nb4.77Te4 belongs to the compounds crystallizing to the tetragonal Ti5Te4 structure type. It undergoes a transition to superconductivity at critical temperature Tc = 0.6–0.9 K. In the normal state a nonmonotonic temperature dependence of the resistivity was observed, and two characteristic local maxima at T ≈ 2 and 30 K have been ascertained. The position of the low-temperature maximum correlates with Tc, which has been interpreted as an interplay of electronelectron interaction in the diffusion and Cooper channels. The hightemperature maximum can also be interpreted in terms of the interference effects as a result of competition between the weak localization and the weak antilocalization of conduction electrons. The magnetoresistance data have been interpreted according to the MakiThompson-Larkin effect and electron-electron interaction in the Cooper channel. The compound Ta1.2Nb3.4Te4 has a monoclinic crystal structure, being a superconductor with Tc = 1.3 K. In the normal state the magnetoresistance is determined by the quantum interference effects. The dephasing time of conduction electrons extracted from the magnetoresistance data was determined by the electron-electron interaction. Similar to Nb4.77Te4 the temperature dependence of the resistivity in Ta1.2Nb3.4Te4 is nonmonotonic but with two maxima at 4 and 14 K.[215] 108 • Biannual Report 2004/2005 Localized electromagnetic waves The scalar free-space wave equation has a class of solutions that seemingly defy the laws of diffraction and can preserve very sharp spatial and temporal localization in the course of propagation over the distances that many times exceed the Rayleigh range. During the past few years the experimental generation of localized waves has been put in solid terms and we have moved on in two directions: (i) finding new theoretical models of strongly localized waves for realization in the optical domain, (ii) transferring the know-how obtained in working with classical fields into the domain of quantum optics. The following main results have been obtained. Simple practical model approximations to the so-called focused X wave – a pulsed wave propagating superluminally in vacuum or in a linear medium, which attracts attention due to its spread-free strong spatial localization – have been derived. The experimental feasibility of the model waves in the optical domain has been shown and their radial decay analysed. In contradistinction to a widespread belief that the spatial localization of photons is restricted by a power-law falloff of the photon energy density we have shown that for certain specifically designed cylindrical one-photon states the localization is exponential or even better in lateral directions. If the photon state is built from the socalled focus wave mode, the falloff in the waist cross-section plane turns out to be quadratically exponential (Gaussian) and such strong localization persists in the course of propagation [206]. More detailed overview of these results the reader can find in Section “Research Highlights” of this Report. Multiphoton processes in intense laser fields In recent years, interesting and unusual features of the so-called nondiffractive or propagation-invariant light beams have attracted considerable interest in applications of such beams in nonlinear Scientific Report • 109 optics. In most cases the simplest coherent conical beams like Bessel beams were used, but much less is known about nonlinear optical processes driven by incoherent conical beams. Recently several evidences have been found that conical excitation geometry allows one to preserve a relatively high efficiency of a nonlinear process even for laser beams with significantly degraded beam quality. Such a tolerance may be very interesting and useful feature of conical beams in the excitation of nonlinear optical processes and frequency conversion of laser emission. Resonance-enhanced four-wave mixing and generation of sumfrequency field in xenon have been studied under two-color excitation by spatially coherent and incoherent conical laser beams. Comparisons of analogous results with a two-color excitation in an ordinary geometry of focused beams and in one-color Bessel beams have been made. It has been shown that with incoherent laser beams the fourwave mixing process is much less degraded in conical excitation geometry where an efficient generation of sum-frequency field can be obtained despite of multiple wave-front aberrations. Such a tolerance of conical beams results from their specific structure of coherent focal domains that are extended significantly along the beam axis. It preserves a relatively high degree of coherence for excitation processes even for input beams with poor spatial coherence. Numerical simulation of sum-frequency excitation profiles for one- and twocolor conical beams has been carried out and good agreement with experimental observations has been obtained. Spectroscopy of plasmo-chemical processes in the active media of discharge pumped UV-VUV gas lasers The high-current powerful (~50 MW/cm3), pulsed (~10 ns) homogeneous volume discharge in high-pressure (up to 10 bar) argon has been comprehensively investigated with ns time-resolved spectroscopic diagnostic techniques. Importance of this subject is connected with the development of efficient excimer light sources and possible 110 • Biannual Report 2004/2005 using of rare gases discharge plasmas as VUV laser active media. The aim of this work is revealing of energy flow kinetics in high-pressure discharge plasma. Spatial-time behaviours of the main excited atomic species and electrons were monitored from VUV-VIS spontaneous emission spectra of the discharge. It was revealed, that broad (200–850 nm) UV-VIS continuum is caused mainly by photorecombination of electrons with Ar2+ ions. Emission intensities from this continuum and red Ar* lines have a typical recombination behavior in the afterglow stage of the discharge (square root of its intensity is proportional to the electron density). Time dependences of Ar* (4S, 4P), Ar2*(36u) densities were measured by the pulse dye laser absorption probing of the discharge plasma. Quantitative experimental data about densities of key excited atomic and molecular species are very important for understanding of discharge pumping efficiency and how close to the lasing-threshold conditions we are able to approach in our real discharge devices. Experimentally obtained temporal dependencies of several excited species are compared with calculated ones. Strong optical dynamic aberrations in the discharge plasma are observed for the probing laser beam at high pumping power density conditions. These phase aberrations is caused by negative contribution of free electrons to the refraction index. Possible mechanisms responsible for the experimentally observed saturation of Ar2* VUV (126 nm) emission output with increase of the pumping power were analysed on the basis of received plasma parameters. Optical dynamic aberration could be the main limiting factor for using of discharge plasma as a laser active medium at high pumping power density conditions. Scientific Report • 111 Stark absorption spectroscopy of indole and 3-methylindole Electroabsorption (EA) or Stark effect spectroscopy implies the measurement of the spectrum of a small (~0.1%) change in sample absorbance induced by a strong (~1 MV/cm) externally applied electric field. According to the theory, which takes into account the Stark shift of the transition frequency and the field-induced reorientation effects for a mobile ensemble of polar absorbing molecules at thermal equilibrium, the change in absorbance scales quadratically with the field strength and the EA spectrum of a given band can be expressed as a linear combination of the zeroth, the first, and the second derivatives of the absorption spectrum of that band. We analysed room-temperature UV (240–320 nm) absorption and EA spectra of biomimetic molecules indole and 3-MI, doped into a polymethylmethacrylate (PMMA) film. By a model fit the simulated EA and absorption spectra to the measured ones, the spectra are decomposed to the contributions from threeSS* type singlet electronic transitions (to the La, Lb, and Bb excited states) and several molecular parameters, for example the change in permanent dipole moment and the change in polarizability accompanying the transition to the La state, are obtained. Analysis of the changes in the shape of the EA spectrum as a function of the angle between the polarization direction of the absorbing light and the direction of the applied electric field proved that polar indole and 3-MI molecules are partially reorientated towards the electric field in the room-temperature PMMA matrix. Measurements at 50K, where the angular mobility of indole and 3-MI molecules in PMMA is doubtlessly frozen, confirmed the absence of field-induced orientation/alignment effects in the EA spectra. [240] 112 • Biannual Report 2004/2005 Laser physics outside physics – copper vapour laser system for medical applications Efficacy of treatment in nowadays medicine essentially depends on the development of technology. This general rule also applies to the laser medicine, and more specifically, to the lasers used for the cure of skin diseases. A copper vapour laser (emitting at 511 and 578 nm) has been used for this purpose already for 10 years in the Dermatological Clinic of the University of Tartu. This original laser system has been designed and manufactured as a result of fruitful collaboration between the Institute of Physics (IP) and the Estonian laser firm “Estla”. Results of the laser treatment of various skin diseases (acne, allergodermatoses, leg ulcers, etc.) as well as skin defects (teleangiectatic lesions) have been very good (see Fig. 1): the percentage of recovery exceeds 70. No side-effects have been noticed, the laser emission is well tolerated by the patients and it does not interact with systematic or topical medicines. Laser cure has been introduced as a standard method of treatment in the Dermatological Clinic (15–20 patients per day). Two years’ experience in the Clinic of small domestic animals shows that the green and yellow Cu laser emission with intensity of 200 mW is also very effective in the cure of skin diseases and other inflammations of domestic animals (dogs, cats, rabbits, etc.). An essential step forward (achieved in collaboration between the IP and “Estla”) was the implementation of a more powerful (3 W) Cu laser in the Dermatological Clinic. This new laser is provided with an electronic shutter, which enables pulsed (from 0.1 to 1 s) irradiation of skin defects. Therefore, relaxation of heat occurs during the pauses between the pulses, which means that the higher intensity of the irradiation can be used. Consequently, skin defects can be removed more quickly and more utterly. The patient, a 30 years old car locksmith, was suffering with allergodermatosis. x First picture shows the situation before the laser cure was initiated. x Two days after the first 30 minutes’ laser treatment. x Five days after the second 30 minutes’ laser treatment. Figure 1. Demonstration of the efficacy of Cu laser treatment. Figure 2. Explicit demonstration of the Levinson theorem (¥(0) -¥(∞) = Nπ) for Xe2. As needed,¥(0) = 24π, since the system has 24 bound states. At E = 3.146294 meV, the phase shift passes a zero, it has a minimum at E ≈ 2932 eV, and very slowly approaches the limit (¥(∞) = 0) as E ∞. The left-side inset shows nearly linear dependence on the wave number k as E =ʄ2k2/2m 0, in full agreement with general-theoretical concepts. In the right-side inset one can see that the phase curve has an inflection point near V(0) (the potential energy at the origin). Scientific Report • 113 A new approach to the inverse problem in quantum mechanics One-dimensional inverse Schrödinger problem can be solved, i.e., the interaction potential for a confining one-dimensional quantum system can be uniquely determined, if and only if the following complete set of information is available: x Full energy spectrum of the bound states (En < 0, n = 1, 2, …, N). x Full energy dependence (from 0 to ∞) of the phase shift (E) for the scattering states. x N additional real parameters related to relevant bound states that uniquely fix their normalization. Unfortunately, all these obligatory data are never available. In this situation, one may try to construct a reference potential, whose spectral characteristics should be in a reasonable agreement with available data on the system's properties. Since the reference potential is fixed, it is always possible to calculate all its spectral characteristics, including the phase shift for the full range of scattering states, and the Jost function. Such an approach has been developed on example of diatomic xenon molecule in its ground electronic state. An exactly solvable reference potential for this system has been constructed, which enables to solve the related energy eigenvalue problem exactly. Moreover, the full energy dependence of the phase shift can also be calculated analytically, and as a particular result, full agreement with Levinson theorem has been achieved and explicitly demonstrated (see Fig. 2). Provided with full spectral information about the reference potential, one can, in principle, calculate an improved potential for the system. For example, one can construct a potential whose bound states would coincide with the “real” discrete energy levels. To this end, a two-step scheme has been proposed which combines the well- 114 • Biannual Report 2004/2005 known Gelfand-Levitan and Krein methods for the solution of the inverse problem. [264–267] Compiled by Peeter Saari Fundamental phenomena in wide-gap materials and their prospects of application The main aim of the present project (2002–2006) was to investigate the fundamental peculiarities of relaxation, localization, decay and multiplication of electronic excitations (quasi-particles) in wide-gap (Eg=5–15 eV) inorganic dielectrics, based on metal oxides and halides, and to analyse the usage prospects of these processes for elaborating new and improving the existing dielectrics, widely used for various technical applications. One of the main aspects of investigations in 2004–2005 was the elucidation and experimental testing the prospects for increasing the radiation resistance of construction materials for tritium-deuterium fusion reactors. The planned experimental and powerful industrial reactors have several advantages with respect to nuclear reactors based on fission of heavy nuclei. Thermonuclear energetics is alluring not only due to extended reproduction of fuel (hydrogen isotopes); it is also environmental-benign (there is no release of CO2 responsible for “greenhouse” effect, other unhealthy gases and radioactive waste) and secure against terrorist attacks. However, the radiation resistance of the existing materials for powerful fusion reactors is on its breaking point and should be significantly increased. The another priority of our applied research was determined by the contracts with SAMSUNG SDI (since 2005) connected with the research and development of plasma display panels (PDP) used in large-dimension modern TV sets, where scanning electron beam is replaced by point discharges of xenon emission (vacuum ultraviolet (VUV) resonant Scientific Report • 115 emission at 8.43 eV). New dielectric materials with lower discharge firing voltage has to be elaborated and VUV xenon emission should be transformed into green, blue and red light with optimal characteristics by means of radiation-resistant spectral transformer. Particular emphasis has been placed on radiation-resistant binary metal oxides and fluorides promising for thermonuclear energetics, PDP and new generation of fast detectors and selective dosimeters of radiation. Basic peculiarities of the processes of relaxation, localization, multiplication and decay channels (with emission, heat release and especially with the creation of structural defects) of electronic excitations (EEs) have been investigated in binary wide-gap materials with simple structure – LiF, BaF2, MgO and various modifications of Al2O3, glasses and crystals of SiO2. The peculiarities of energy spectra and radiation processes in more complex systems – metal tungstates and suphates (Me = Mg, Ca, Sr, Ba, Pb), lithium silicates, aluminates (BaMgAl10O17, Ca12Al14O33, Lu3Al5O12, etc) have been studied as well. In these materials the energy gap Eg varies in a wide range and, in contrast to metal halides, the v-band is complex and energetically wide (Ev = 4–10 eV) resulting in important features of hole processes. The main distinctive feature of our experimental approach is the usage of the exciting photons in a wide energy range (5–2000 eV, incl. synchrotron radiation facilities of MAX-lab, Lund and HASYLAB at DESY, Hamburg), electrons of various energies (1–300 keV) and a wide temperature range of experiments (1–750 K) by means of the methods of optical, X-ray, electron, time-of-flight mass and thermoactivation spectroscopy, and EPR method. The study of wide-gap crystals and thin films of several types using VUV and XUV (soft X-ray) photons turned out to be very informative. Such photons cause a selective creation of EEs in inner and outer cation shells, oxygen ions, complex oxyanions as well as the formation of groups of several spatially correlated quasi-particles. The peculiarities of the processes of relaxation, self-trapping and decay of anion and cation excitons have been revealed and the features of hole 116 • Biannual Report 2004/2005 processes have been investigated for the first time in metal oxides with wide and structured v-band. Several novel effects have been revealed in wide-gap materials under conditions of high-density irradiation by powerful electron pulses or heavy swift ions. The effects connected with high density of excitations are particularly important in the search for increasing the radiation resistance of materials for fusion reactors, optical windows for short-wavelength lithography and for selective dosimetry of fast neutrons and novel fast scintillators. The results obtained in 2004–2005 were published in 67 articles (including 45 CC contributions) and presented at 16 international conferences (19 talks, 4 of those invited, and 27 poster presentations). The main results can be divided into several groups as follows. Defect creation by hot electron-hole recombination in oxides Among binary crystals there are several wide-gap oxides (MgO, Al2O3, SiO2 etc.) whose radiation resistance against X-irradiation is hundreds times higher than in alkali halide crystals. Such difference is conditioned by the fact that the creation energy of Frenkel pair (FP) (FP > Eg and the recombination of relaxed (cold) electrons (e) and holes (h) does not cause the creation of FPs. However, even these oxides are insufficiently stable against radiation providing high density of EEs. For example, irradiation of SiO2 by a powerful 6 keV-electron beam leads to the creation of radiation defects at 8 K [11, 69]. It has been proposed that the effect is caused by a complex structure of v-band of SiO2. Measuring the spectra of fast (subnanosecond) hole intraband luminescence (h-IBL) it was shown that, in contrast to MgO, crystalline and amorphous quartz possesses a wide v-band divided into subbands separated by the energy gap of ~1.5 eV. This gap impedes the relaxation of the holes, formed at the irradiation in a lower subband, and facilitates the efficient hot e-h recombination resulting in the energy release higher than (FP. A similar energy gap inside the v-band was revealed in K2SO4 and Scientific Report • 117 Rb2SO4 crystals, while it is absent in more radiation resistant (among other sulphates) CaSO4 crystal [101, 208]. According to our experiments, the efficiency of hot recombination can be drastically decreased in MgO crystals (samples were grown at the Institute) with a continuous v-band (without splitting) at the expense of the direct excitation of luminescent Cr3+ impurity ions by hot electrons. A further experimental and theoretical study of this mechanism of “luminescent protection” against radiation defect creation at e-h recombination lies ahead. Comparative study of MgO and SiO2 crystals possessing wide v-bands with different structure (continuous in MgO or split into two subbands in D-quartz) has been started. The irradiation of these two materials by 238U swift ions (kinetic energy of 2.5 GeV, fluence 1012 ions/cm2), i.e. under the same conditions of extremely high mean energy loss leads to rather different results. MgO crystals demonstrate significantly higher radiation resistance and hold their initial crystalline structure in spite of high concentration of F and F+ centres. On the other hand, there is a layering in the region of SiO2 that coincides with the range of uranium ions. A comparison of the radiation effects in ion-irradiated pure and doped MgO single crystals (grown at the Institute) with those under irradiation by fast neutrons (fluences between 106 and 3u1011 n/cm2, Ural State Technical University) has been started as well. Fast neutrons efficiently create F+ centres with appropriate absorption band of and high-temperature TSL peaks at 630 and 725 K. The localization of holes in the single crystals MgO:Be MgO:Ca, grown in IPUT, was investigated. In MgO, where a self-trapping of holes has not been detected, the holes trapped by the isoelectronic impurities are the closest analogue of self-trapped holes. As a result of optical, thermoactivation and EPR measurements, the optical characteristics and delocalization temperature of the holes, trapped by Be and Ca impurities, were determined. By EPR method, the structure of the center, created at the localization of a hole by a Be2+ centre and 118 • Biannual Report 2004/2005 the spin-relaxation parameters, characterising the interaction between the hole and the crystal lattice, were determined. It was found that the Be ion in a cation site acts as a trapping center for both electrons and holes. [13, 141, 149] Pure and doped with germanium or oxygen thermally stable Li4SO4 ceramics, considered as promising blanket materials for fusion reactors, were synthesized. Electron-hole and interstitial-vacancy processes have been investigated for the first time at 5–200 K in highly pure Li4SO4 ceramics irradiated by electrons or 4–30 eV photons. Low-temperature thermally stimulated luminescence (TSL) as well as photostimulated luminescence (PSL) of ~2 V were detected. The regions of fundamental and defect-related regions were separated measuring the creation spectra of TSL peaks and PSL. Luminescent methods allow to perform comparative testing of Li4SO4 ceramics prepared by different technologies. [234] Decay of a cation exciton with the formation of an anion exciton in LiF A short-wavelength analogue of the Raman effect, when excitons act as phonons at the scattering of X-rays, was theoretically considered by Agranovich and Ginzburg back in 1961. Previously we experimentally revealed the decay of a cation exciton (Ec # 34 V) into one anion exciton (Ea # 8 and 7 V, respectively) and several e-h pairs in NaCl and NaBr crystals. In 2005 the decay process of a cation exciton with the formation of an anion one was revealed and thoroughly studied in a LiF crystal (Ec # 62 V, Ea # 13 V) at 4.2–200 K. This important result is considered in details in research highlights on pp. 39–41. Here we will only point out that this effect should be searched for in lithium-containing dielectrics – promising blanket materials for thermonuclear energetics. Using a complex of thermoactivation spectroscopy methods, model LiF crystals have been studied for the first time in a wide temperature region from 2.5 to 800 K (see also [78, 222]). Scientific Report • 119 Decay of anion excitons into F-H pairs in LiF crystals The e-h processes in tissue-equivalent LiF crystals doped with magnesium and titanium are usefully employed for personal J-dosimetry. However, these systems still turned out to be unsuitable for the selective detection of fast neutrons. The peculiarity of anion exciton decay into an FP in LiF, 1aF and NaCl crystals lies in the fact that an H center, formed simultaneously with an F center, is oriented along <111> directions, while in other alkali halides H interstitials are oriented along <110> closely-packed anion rows and the crowdion mechanism even at 5 K facilitates spatial separation of defects and formation of stable F-H pairs. In LiF, the crowdion motion of H interstitials is impossible and mainly short-lived (< 10 s) F-H pairs are formed by X-irradiation at 5 K. Additional heating up to 40–60 K is needed for defect separation inside FPs. [78, 222] In collaboration with German colleagues from GSI (Darmstadt) it was shown that the irradiation of LiF crystals by heavy swift ions or D-particles causes a local heating in ion tracks sufficient for the transformation of F-H pairs into more thermally stable – and –VK pairs. In nominally pure and doped with various impurities LiF crystals, such kind of irradiation at room temperature leads to the formation of more complex defect associations, part of which remains stable even at T > 600 K (TSL peaks at 650 and 740 K, heating rate of 2.86 K/s). The intensity of these high-temperature TSL peaks in LiF crystals ion-irradiated under the conditions of high excitation density is significantly higher than in the case of X- or VUV-irradiation. At the same time, local heating along ion tracks (with radius up to 15 nm) suppresses the dosimetric TSL peaks at 450–500 K. [251] 120 • Biannual Report 2004/2005 Solid-state spectral transformers and secondary electron emitters for PDPs In recent years many dozens of dielectric materials with different function mechanisms were tested in many laboratories of research institutes and companies as spectral transformers of resonant xenon discharge emission (hQ = 8.43 eV) into blue, green and red light in plasma display panels. A dozen phosphors with a quantum yield of QY = 0.8–1.0 at hQ = 8.43 eV has been found, but neither of them possesses a sufficient radiation resistance. In addition, because of low values of the receptivity constants for red elements of a human eye, the use of existing efficient green phosphors requires the red emitters with QY > 1. Widely used blue phosphor BaMgAl10O17:Eu2+ (BAM:Eu2+) as well several its modifications – BAM:Mn2+, SrMgAl10O17:Eu2+ (SAM:Eu2+), BaMgAl14O23:Eu2+ have been synthesized at the Institute and thoroughly studied in a wide region of exciting photons of 5–30 eV. In a classic BAM:Eu2+ phosphor (QY = 0.95r0.05 at hQ = 8.43 eV) the value of QY > 1 has been detected in the spectral region of 12–20 eV. This revealed new “hole” mechanism of photon multiplication (photon cutting) is connected with the transfer of the energy excess of hot holes to luminescent Eu2+ ions. Several other e-h and excitonic mechanisms of photon multiplication have been considered as well. Unfortunately, the spectral transformers for xenon discharge emission with real values of QY > 1 have not been elaborated yet. In 2005 a number of red phosphors (a search for them is especially urgent at the present time) based on YO2S:Eu3+ and several complex borates have been tested at the Institute. [44, 162, 185, 252] Very important issue for the development of PDPs is a further improvement of a dielectric layer, which should provide efficient emission of secondary electrons determining the operating voltage of PDP. Such task is complicated while the dielectric layer also protects electrodes from damage by energetic ions created in gas discharge. According to the contract with SAMSUNG SDI, cathodo- Scientific Report • 121 luminescence spectroscopy was applied for the investigation of MgO films in an effort to compare their electronic properties with those for single crystals. Another contract is dedicated for the elaboration of new dielectric materials, which performance is expected to be better than of the layers presently used in commercially available TV sets. Physical processes in tungstates and other scintillators Spectroscopic study of various scintillation materials for high-energy physics and medical imaging systems was carried out. Luminescence and defects creation processes were studied at 0.4–300 K for many undoped and doped PbWO4 crystals with different concentrations of various impurity and intrinsic defects, grown by different methods and annealed at different conditions. Complex structure of the blue WO42––related and green MoO42––related emission bands was found and their origin established. For the first time, various localized exciton states were identified. Photo/thermally stimulated decay of the self-trapped and localized excitons and defect-related states into stable defects was systematically studied and the corresponding activation energies calculated. Luminescence thermal quenching was explained by the decay of the corresponding exciton- or defect-related state. [8, 10, 64, 139, 175] Luminescence and defects creation processes were studied for the undoped and Ce3+-doped single crystals of yttrium-aluminium and lutetium-aluminium garnets and perovskites under selective excitation in the 3.5–11.5 eV energy range. Luminescence characteristics of the self-trapped excitons and the excitons localized near antisite defects (YAl3+ and LuAl3+) and impurity ions were identified. It was found that the antisite defects compete with Ce3+ ions in the processes of energy transfer from the host lattice and negatively influence the decay kinetics and light yield of these materials. For the first time the characteristics of Pr3+-doped garnets were determined. It was found that this fast and effective scintillation material could successfully replace 122 • Biannual Report 2004/2005 Ce3+-doped crystals in some applications. [9, 64, 136, 138, 174, 189, 230, 231] To understand charge-transfer processes in the scintillation materials studied, simple model systems of two types were studied: the crystals containing effective traps for electrons (e.g., CsBr:Tl ) and the crystals without such traps (e.g., KI:Eu). As a result of charge transfer, the localized exciton state is created in the former case. The self-trapped exciton emission and exciton decay into F-H -type defects were observed in the latter case. [130, 223] Particular emphasis was put on the separation of excitonic and e-h processes in crystals with different cations (Ca, Cd, Zn, Al) and oxyanions (WO4, MoO4, SO4). The e-h processes were studied mainly by means of recombination luminescence. The nature of recombination luminescence was studied in detail in pure and doped ZnWO4 crystals. A self-trapped hole was shown to be the main partner in both, thermally induced and photostimulated recombinations. It was shown that in crystals characterized by a strong covalent bonding in oxyanions, only Frenkel excitons are created close to the bottom of the conduction band due to the transitions within the oxyanionic states, while free electrons and holes are created 1–4 eV above the fundamental absorption edge. In CaSO4, e-h pairs are created even due to the lowest-energy transitions between the states of SO4 complexes. The processes of energy transport between the host lattice and impurity centres were studied in several crystals (CaWO4:Bi, ZnWO4:Fe,Mo, Al2(WO4)3:Eu). The nature of the relaxed excited state was determined by the methods of polarized time-resolved spectroscopy in pure and doped CaWO4 and ZnWO4 crystals. The triplet states of unperturbed or impurity perturbed oxyanionic (WO4, MoO4) excitons were shown to be responsible for the main emission bands in these crystals. The study was performed in collaboration with Hungarian, Latvian, Dutch and Swedish scientists. [36, 46, 87, 172, 188, 233, 235] Scientific Report • 123 Diagnostics of novel insulator materials using luminescence spectroscopy VUV spectroscopy was applied in studies of several thin oxide films (HfO2, ZrO2, Al2O3) prepared by atomic layer deposition methods. Such films have a great potential for technological applications as novel insulator layers in electronics and as converters of ionizing radiation in X-ray microtomography devices. It was shown that the intrinsic emission is due to the radiative decay of self-trapped excitons (STEs). Also the energetic parameters as the energy gap, lifetime of STEs, etc. of substances in different crystallographic modifications were determined. [3, 159, 162, 183, 225, 244] Systematic investigation of energy transfer processes was carried out for Eu doped LiCaAlF6 and LiSrAlF6 crystals, which have potential applications in lightening (Eu2+ emits in blue and Eu3+ in red), scintillation as well as in dosimetry. It was established that during the crystal growth Eu ions enter into LiCaAlF6 lattice in biand trivalent state resulting in the emissions due to the 5d o 4f (a370 nm) and 4f o 4f (a590 nm) transitions. The 4f emissions of Eu3+ ions are efficiently excited through the 4f o 4f, F– o Eu3+ charge transfer transitions and the excitonic states localized near impurity. The yield of the 5d o 4f emission of Eu2+ is high in the intra-center excitation and is considerably less in the host absorption limiting their performance for scintillation purposes. [161, 245]. Using a novel light source, the free electron laser built up at DESY (Hamburg, Germany), which provides up to 1013 VUV photons in the ultrashort ( < 50 fs ) pulse, the excitation density effects on the relaxation of electronic excitations in BaF2 and YAG:Ce crystals were investigated. The increased excitation density led to the remarkable shortening of luminescence decays in both crystals. There are several mechanisms (e.g., interaction of spatially close excitations, local heating of crystal, excited state absorption) causing such drastic 124 • Biannual Report 2004/2005 changes in the relaxation dynamics in comparison with effects observed under the excitation by conventional light sources. [160] Compiled by Aleksandr Lushchik Resonant X-ray scattering (RIXS) studies The excitation-decay processes at the F 1s photoabsorption edge in LiF crystal are studied using resonant inelastic x-ray scattering spectroscopy (RIXS). The Raman-type linear dispersion and the narrowing of the x-ray fluorescence peak are observed at resonant excitation. A theoretical model based on the Kramers-Heisenberg formula describes well the main features in fluorescence spectra and allows one to separate the contributions of the exciton and the conduction states in the scattering spectra. At the same time, the role of the shape of the spectral distribution within the incident radiation is emphasized as being critically sensitive to the number, kind, and onset of the spectral features, which finally appear in the scattering spectra at a particular incident photon energy, particularly in the subthreshold excitation region. Contrary to case of LiF, core excitons were not identified in O 1s photoabsorption edge of MgO as the narrowing of the X-ray fluorescence peak was not observed. New types of states in LiCl, where both Li core electrons are excited, have been observed in RIXS. States with one, as well as both, of the excited electrons localized at the site of the bare Li nucleus are identified. The results add a dimension to the hypersatellite concept in x-ray emission, and demonstrate that resonant spectroscopy involving multiple core vacancies provides information about decay dynamics, electron correlation, and chemical environment. [7, 28, 156] Scientific Report • 125 Studies of fullerenes Vibronic coupling in solid C60 has been investigated with a combination of resonant photoemission spectroscopy (RPES) and RIXS. Excitation as a function of energy within the lowest unoccupied molecular orbital resonance yielded strong oscillations in intensity and dispersion in RPES, and a strong inelastic component in RIXS. Reconciling these two observations establishes that vibronic coupling in this core hole excitation leads to predominantly inelastic scattering and localization of the excited vibrations on the molecule on a femtosecond time scale. The coupling extends throughout the widths of the frontier valence bands. The significant angle-dependence in the core level and valence line shapes of photoelectron spectra of single crystal K3C60 has been detected. This allowed the identification of bulk and surface components in the data, and allows us to explain the anomalous line shapes observed for this system. The states near the Fermi level are associated with the bulk of the sample. There is strong evidence of an insulating surface layer, which we ascribe to intermolecular electron correlations. These results simplify the interpretation of previous, apparently conflicting observations. [165, 209] Photoelectron spectroscopy of thin insulating films Solid-state effects in the creation and decay of K 2p core excitations in thin KF films on Cu(100) surface have been studied in resonant Auger spectra, excited using synchrotron radiation. The spectra of films of various thickness starting from a single monolayer were measured. The photoabsorption spectra reveal crystal field splitting already at film thickness of about 1 monolayer. The Auger decay spectra of the K 2p–13d core excitations in films of thickness up to 2 monolayers exhibit a band characteristic of the decay of core ionised states, showing that the excited electron delocalises into substrate before the core hole decays. In thicker films the coexistence of the decay of excited states in the bulk of the KF crystalline film and of 126 • Biannual Report 2004/2005 ionised states at the KF–metal interface is observed, indicating that the charge transfer probability from the upper layers of the film into the metallic substrate is strongly reduced. Photoelectron spectroscopy has been used for the studies of HfO2 films, prepared by atomic layer deposition from HfCl4 and H2O on Si(100) in the temperature range of 300–600°C. At low temperatures, films grow faster and are structurally more disordered, compared to films grown at high temperatures. At high temperatures, the films are better crystallized, but grow slower and contain grain boundaries extending from substrate to gate electrode. [157, 180] Time-of-flight and photoelectron spectroscopy of molecules of alkali halides Photoionisation and photofragmentation of molecular rubidium halides following photoexcitation in the vacuum ultraviolet region are investigated by using time-of-flight mass spectroscopy and photoelectron spectroscopy. For this purpose total and partial ion yield spectra are measured from the vapours of RbF, RbCl, RbBr and RbI. Two different decay channels – spectator and participator type – are studied in different rubidium halide molecules. It is demonstrated that the opening of the spectator channel takes place at different excitation energies, depending on the halide atom in the molecule. [164] Photoelectron spectra excited at resonances and between resonances are measured as well. Although all studied molecules have very similar electronstructure, photoelectron spectra show up remarkable difference. This can be explained according to the model, where the ratio between nuclear vibrational period and the electronic decay lifetime play a decisive role. [164, 232] Absorption spectra of CsCl molecule and dimer were measured by using time-of-flight technique in the photon energy region of 5p excitations of Cs. The experimental spectra was analyzed by means of point-charge-molecular-field model, which is based on the exact multiple expansion of electrostatic field induced by the ligands Scientific Report • 127 assumed to be point charges and use a complete set of LSJM- states in diagonalization. The calculations show strong inter-configuration mixing between the states originated from the excited 5p55d and 5p56s configurations. A good accordance between the measured and theoretical spectra shows that proposed calculation model provide a good base for the interpretation of the lowest excitations of the molecules with ionic bonding. [204] Compiled by Arvo Kikas 5. PUBLICATIONS PAPERS 2004 1. J. Aarik, A. Aidla, A. Kikas , T. Käämbre, R. Rammula, P. Ritslaid, T. Uustare, V. Sammelselg, “Effects of precursors on nucleation in atomic layer deposition of HfO2,” Appl. Surf. Sci., 230, pp. 292–300, 2004. 2. J. Aarik, V. Bichevin, I. Jõgi, H. Käämbre, M. Laan, V. Sammelselg, “Fowler-Nordheim tunnelling in Au-TiO2-Ag film structures,” Central European J. Phys., 2, pp. 147–159, 2004. 3. J. Aarik, H. Mändar, M. Kirm, L. Pung, “Optical characterization of HfO2 thin films grown by atomic layer deposition,” Thin Solid Films, 466, pp. 41–47, 2004. 4. P. Adamson, “Reflection of light in a long-wavelength approximation from a N-layer systm of inhomogeneous dielectric films and optical diagnostics of ultrathin layers. II Transparent substrate,” J. Opt. Soc. Am. B, 21, pp. 645–654, 2004. 5. P. Adamson, “High-aperture focusing systems: control of light concentration in focal region by pupil filtering,” J. Modern Optics, 51, No. 1, pp. 65–74, 2004. 6. P. Adamson, “Laser diagnostics of nanoscale dielectric films on transparent substrate by integrating differential reflectivity and ellipsometry,” Optics & Laser Technology, 36, No. 8, pp. 661–668, 2004. 7. M. Agåker, J. Söderström, T. Käämbre, C. Glover, L. Gridneva, T. Schmitt, A. Augustsson, M. Mattesini, R. Ahuja, J.-E. Rubensson, “Resonant inelastic soft X-ray scattering at hollow lithium states in solid LiCl,” Phys. Rev. Lett., 93, pp. 016404, 2004. 8. V. Babin, P. Bohacek, E. Bender, A. Krasnikov, E. Mihokova, M. Nikl, N. Senguttuvan, A. Stolovits, Y. Usuki, S. Zazubovich, “Decay kinetics of green emission in tungstates and molybdates,” Radiat. Measurements, 38, pp. 533–537, 2004. Publications • 129 9. K. Blazek, A. Krasnikov, K. Nejezchleb, M. Nikl, T. Savikhina, S. Zazubovich, “Luminescence and defects creation in Ce3+doped Lu3Al5O12 crystals,” Phys. stat. sol. (b), 241, pp. 1134–1140, 2004. 10. P. Bohacek, N. Senguttuvan, V. Kiisk, A. Krasnikov, M. Nikl, I. Sildos, Y. Usuki, S. Zazubovich, “Red emission of PbWO4 crystals,” Radiat. Measurements, 38, pp. 623–626, 2004. 11. M. Cannas, S. Angello, F. M. Gelardi, R. Boscaino, A. N. Trukhin, P. Liblik, Ch. Lushchik, M. F. Kink, Y. Maksimov, R. A. Kink, “Luminescence of J-radiation induced defects in D-quartz,” J.Phys.: Condens. Matter, 16, pp. 7931–7939, 2004. 12. D. Di Martino, A. Krasnikov, M. Nikl, A. Vedda, S. Zazubovich, “The 3.83 eV luminescence of Gd-enriched phosphate glasses,” Phys. stat. sol. (a), 201, pp. R38–R40, 2004. 13. S. A. Dolgov, V. Isakhanyan, T. Kärner, P. Liblik, A. Maaroos, S. Nakonechnyi, “Luminescence of [Be]+-centre in MgO:Be,” Radiat. Measurements, 38, pp. 699–702, 2004. 14. S. Dueñas, H. Castán, H. Garc a, J. Barbolla, K. Kukli, J. Aarik, “Effect of growth temperature and postmetallization annealing on the interface and dielectric quality of atomic layer deposited HfO2 on p and n silicon,” J. Appl. Phys., 96, pp. 1365–1372, 2004. 15. S. Dueñas, H. Castán, H. Garc a, J. Barbolla, K. Kukli, J. Aarik, A. Aidla, “The electrical-interface quality of as-grown atomic-layerdeposited disordered HfO2 on p- and n-type silicon,” Semicond. Sci. Technol., 19, pp. 1141–1148, 2004. 16. A. Ellervee, J. Linnanto, A. Freiberg, “Spectroscopic and quantum chemical study of pressure effects on solvated chlorophyll,” Chem.Phys. Lett., 394, pp. 80–84, 2004. 17. M. Faarinen, S. Bazhal, U. Falkengren-Grerup, R. Hellborg, M. Kiisk, C.E. Magnusson, P. Persson, G. Skog, K. Stenström, “26Al at the AMS facility in Lund,” Nucl. Instr. and Meth., Elsevier, London, B223–224, No. August, pp. 130–134, 2004. 18. V. Fedossejev, “Pecluriarities of the reflection of light beam with optical voticies,” Proc. SPIE, 5481, pp. 154–159, 2004. 19. A. Freiberg, M. Rätsep, K. Timpmann, G. Trinkunas, “Dual fluorescence of single LH2 antenna nanorings ,” J. Lumin., 108, pp. 107– 110, 2004. 130 • Biannual Report 2004/2005 20. M. Friedrich, W. Pilz, N. Bekris, M. Glugla, M. Kiisk, V. Liechtenstein, “A small and compact AMS facility for tritium depth profiling,” Nucl. Instr. Meth., Elsevier, London, B223–224, pp. 21–25, 2004. 21. A. Gall, A. Ellervee, B. Robert, A. Freiberg, “The effect of internal voids in membrane proteins: high pressure study of two membrane proteins from Rhodobacter sphaeroides,” FEBS Letters, 560, pp. 221–225, 2004. 22. V. Hizhnyakov, V. Boltrushko, H. Kaasik, I. Sildos, “Phase relaxation in the vicinity of the dynamic instability: anomalous temperature dependence of zero-phonon line,” J. Lumin., 107, pp. 351–358, 2004. 23. V. Hizhnyakov, J. Kikas, J. Takahashi, A. Laisaar, A. Suisalu, An. Kuznetsov, “Two-level systems in glasses under high pressure : temperature cycling effect,” Phys. stat. sol. (c), 1, No. 11, pp. 2937–2940, 2004. 24. V. Hizhnyakov, G. Benedek, “Quantum diffusion: effects of local distortion of phonons,” Phys. stat. sol. (c), 1, pp. 3019–3022, 2004. 25. I. Jõgi, J. Aarik, V. Bichevin, H. Käämbre, M. Laan, V. Sammelselg, “Fowler-Nordheim tunnelling in TiO2 films grown by atomic layer deposition on gold substrates,” Proc. Estonian Acad. Sci. Phys. Math., 53, pp. 226–236, 2004. 26. M. Kiisk, R. Hellborg, P. Persson, M. Faarinen, G. Skog, K. Stenström, “The charge state distribution of Be, C, Cl and Al ions at the Lund Pelletron accelerator with the recently modified terminal pumping in use,” Nucl. Instr. and Meth., Elsevier, London, A521, No. April, pp. 299–305, 2004. 27. V. Kiisk, I. Sildos, O. Sild, J. Aarik, “The influence of a waveguiding structure on the excitonic luminescence of anatase thin films,” Opt. Materials, 27, pp. 115–118, 2004. 28. A. Kikas, T. Käämbre, A. Saar, K. Kooser, E. Nõmmiste, I. Martinson, V. Kimberg, S. Polyutov, F. Gel’mukhanov, “Resonant inelastic X-ray scattering at the F 1s photoabsorption edge in LiF. Interplay of excitonic and conduction states, and Stokes’ doubling,” Phys. Rev. B, 70, No. 8, pp. 085102, 2004. 29. A. Kikas, T. Käämbre, A. Saar, K. Kooser, E. Nõmmiste, I. Martinson, V. Kimberg, S. Polyutov, F. Gel’mukhanov, “Erratum: Resonant inelastic X-ray scattering at the F 1s photoabsorption edge in LiF. Interplay of excitonic and conduction states, and Stokes’ doubling (Phys. Rev. B 70, 085102, 2004),” Phys. Rev. B, 70, No. 20, pp. 209902, 2004. Publications • 131 30. I. Kink, V. Kisand, K. Saal, T. Tätte, M. Lobjakas, A. Lõhmus, “Laser ablation for 3D nanometric imaging of solids,” Proc. Estonian Acad. Sci. Eng., 10, No. 1, pp. 30–38, 2004. 31. V. Kisand, E. Kukk, M. Huttula, A. Koivukangas, H. Aksela, E. Nõmmiste, S. Aksela, “Corrigendum: Fragmentation and electronic decay of vacuum ultraviolet-excited resonant states of molecular CsCl,” J. Phys. B: At. Mol. Opt. Phys., 37, pp. 3011, 2004. 32. P. Konsin, B. Sorkin, “Influence of external fields on the properties of SrTi(16O1–x18Ox)3 at oxygen isotope substitution,” Ferroelectrics, 308, pp. 33–37, 2004. 33. P. Konsin, B. Sorkin, “A generalized two-band model for the superconductivity in MgB2,” Supercond. Sci. Technol. 17, pp. 1472–1476, 2004. 34. M. M. Korshunov, S. G. Ovchinnikov, A. V. Sherman, “Spin fluctuations influence on quasiparticle spectrum of realistic p-d model,” J. Magn. and Magnetic Materials, 272–276, pp. e575–e577, 2004. 35. M. M. Korshunov, S. G. Ovchinnikov, A. V. Sherman, “Effective Hamiltonian and properties of the normal and superconducting phases of n-type cuprates,” JETP Letters, 80, No. 1, pp. 39–43, 2004. 36. A. Kotlov, L. Jönsson, M. Kirm, A. Lushchik, V. Nagirnyi, E. Rivkin, A. Watterich, B. I. Zadneprovski, “Luminescence study of self-trapped holes in pure and Fe or Mo doped ZnWO4 crystals,” Radiat. Measurements, 38, pp. 715–718, 2004. 37. N. Kristoffel, P. Rubin, “Superconducting gaps and pseudogaps in a composite model of two-component cuprate,” Physica C, 402, pp. 257– 262, 2004. 38. N. Kristoffel, P. Rubin, “Effect of photodoping on cuprate superconductivity,” Physica C, 418, pp. 49–52, 2004. 39. K. Kukli, J. Aarik, M. Ritala, T. Uustare, T. Sajavaara, J. Lu, J. Sundqvist, A. Aidla, L. Pung, A. Hårsta, M. Leskelä, “Effect of selected atomic layer deposition parameters on the structure and dielectric properties of hafnium oxide films,” J. Appl. Phys., 96, pp. 5298–5307, 2004. 40. P. Kuusk, M. Saal, “A cosmological model of holographic brane gravity,” Gen. Rel. Gravit., 36, No. 5, pp. 1001–1014, 2004. 132 • Biannual Report 2004/2005 41. S. Lange, I. Sildos, V. Kiisk, J. Aarik, “Energy transfer in the photoexcitation of Sm3+ implanted TiO2 thin films,” Mat. Sci. Engineer. B, 112, pp. 87–90, 2004. 42. R.-K. Loide, I. Ots, R. Saar, P. Suurvarik, “On superfield equations of motion,” Hadronic J., 27, pp. 151–163, 2004. 43. J. Lu, J. Sundqvist, M. Ottosson, A. Tarre, A. Rosental, J. Aarik, A. Hårsta, “Microstructure Characterisation of ALD-grown epitaxial SnO2 thin films,” J. Crystal Growth, 260, pp. 191–204, 2004. 44. A. Lushchik, Ch. Lushchik, A. Kotlov, I. Kudryavtseva, A. Maaroos, V. Nagirnyi, E. Vasil’chenko, “Spectral transformers of VUV radiation on the basis of wide-gap oxides,” Radiat. Measurements, 38, pp. 747– 752, 2004. 45. K. Mauring, V. Novoderezhkin, A. Taisova, G. Fetisova, “The model of pigmental aggregation in the chlorosomal antenna of the green bacterium Chloroflexus Aurantiacus,” Molec. Biol., 38, No. 2, pp. 266– 271, 2004. 46. V. Nagirnyi, L. Jönsson, M. Kirm, A. Kotlov, A. Lushchik, I. Martinson, A. Watterich, B. I. Zadneprovski, “Luminescence study of pure and Fe or Mo doped ZnWO4 crystals,” Radiat. Measurements, 38, pp. 519– 522, 2004. 47. I. Ots, H. Uibo, H. Liivat, R.-K. Loide, “Possible anomalous ZZ and Z couplings and Z boson spin orientation in e+e– oZ ,” Nucl. Phys. B, 702, pp. 346–356, 2004. 48. V. Palm, M. Pärs, J. Kikas, “Hole burning and single-molecule spectroscopy of terrylene in incommensurate biphenyl,” J. Lumin., 107, pp. 57– 61, 2004. 49. A. V. Pokropivny, D. Erts, V. V. Pokropivny, A. Lõhmus, R. Lõhmus, H. Olin, “Study of nanoscale contacts with the help of combined TEM-AFM technique and theoretical MD-TM calculations: in situ transformations of gold nanowires,” Phys. Low-Dimens. Struct., No. 1/2, pp. 83–90, 2004. 50. I. Rebane, “Differences of the radiative linewidth in single-impurity molecule spectroscopy,” J. Lumin., 107, pp. 38–41, 2004. 51. Karl K. Rebane, “Purely electronic zero phonon lines. Recent developments,” J. Lumin., 107, pp. 122–128, 2004. Publications • 133 52. K. Reivelt, P. Saari, “The Bessel-Gauss pulse as an appropriate mathematical model for optically realizable localized waves,” Opt. Lett., 29, No. 11, pp. 1176–1178, 2004. 53. I. Renge, “Lennard-Jones model of frequency-selective baro- and thermochromism of spectral holes in glasses,” J. Phys. Chem., 108, No. 29, pp. 10596–10606, 2004. 54. P. Rubin, A. Sherman, “Magnetic properties of the two-dimensional Heisenberg model on a triangular lattice,” Phys. Lett. A, 334, No. 4, pp. 312–316, 2004. 55. R. Ruus, K. Kooser, E. Nõmmiste, A. Saar, I. Martinson, A. Kikas, “Potential barrier effects in Cs 3d resonance photoemission of CsF,” J. Electron Spectrosc. Relat. Phenom., 137–140, pp. 377–381, 2004. 56. P. Saari, K. Reivelt, “Generation and classification of localized waves by Lorentz transformations in Fourier space,” Phys. Rev. E, 69, No. 3, pp. 036612, 1–12, 2004. 57. G. Seibold, F. Becca, P. Rubin, J. Lorenzana, “Time-dependent Gutzwiller theory of magnetic excitations in the Hubbard model,” Phys. Rev. B, 69, No. 15, pp. 155113 (1–12), 2004. 58. A. Sherman, “Magnetic properties of underdoped cuprate perovskites ,” Mol. Phys. Rep., 39, pp. 234–238, 2004. 59. A. Sherman, M. Schreiber, “Low-frequency incommensurate magnetic response in strongly correlated systems,” Phys. Rev. B, 69, No. 10, pp. 100505(R) 1–4, 2004. 60. A. Sherman, “Spectral and magnetic properties of the t-J model of cuprate perovskites,” Phys. stat. sol. (b), 241, No. 9, pp. 2097–2108, 2004. 61. A. Sherman, “Evolution of the hole and spin-excitation spectra of the two-dimensional t-J model: From light to heavy doping,” Phys. Rev. B, 70, No. 18, pp. 184512, 1–4, 2004. 62. I. Sildos, S. Lange, T. Tätte, V. Kiisk, M. Kirm, J. Aarik, “Emission of rare earth ions incorporated into metal oxide thin films and fibres,” Mater. Res. Soc. Proc., 796, pp. 70, 2004. 63. A. Suisalu, M. Jänes, J. Kikas, “Temperature transformation of dopant spectra in incommensurate biphenyl,” J. Phys. Chem. B, 108, No. 29, pp. 10404–10407, 2004. 134 • Biannual Report 2004/2005 64. S. Zazubovich, “New scintillation materials for scientific, medical and industrial applications,” Proc. Estonian Acad. Sci. Phys. Math. , 53, No. 4, pp. 237–251, 2004. 65. I. Tehver, “A possibility of distinguishing the inhomogeneous broadening via coherent Raman spectra,” J. Lumin., 107, pp. 266–270, 2004. 66. I. Tehver, “Calculation of CARS excitation profile of ZnPc,” Phys. stat. sol. (c), 1, No. 11, pp. 3154–3157, 2004. 67. K. Timpmann, G. Trinkunas, J. D. Olsen, C. N. Hunter, A. Freiberg, “Bandwidth of excitons in LH2 bacterial antenna chromoproteins,” Chem.Phys. Lett., 398, pp. 384–388, 2004. 68. K. Timpmann, M. Rätsep, C. N. Hunter, A. Freiberg, “Emitting exciton polaron states in core LH1 and peripheral LH2 bacterial lightharvesting complexes,” J. Phys. Chem. B, 108, pp. 10581–10588, 2004. 69. A. Trukhin, P. Liblik, Ch. Lushchik, J. Jansons, “UV cathodoluminescence of crystalline D-quartz at low temperatures,” J. Lumin., 109, pp. 103–109, 2004. 70. A. N. Trukhin, M. F. Kink, Yu. A. Maksimov, R. A. Kink, T. A. Ermolenko, I. I. Cheremisin, “Luminescence of fluorine-doped and nondoped silica glass excited with an ArF laser,” J. Non-Cryst. Solids, 342, pp. 25–31, 2004. PROCEEDINGS 2004 71. J. Aarik, “Elektroonikamaterjalide tehnoloogia arengu probleemidest ja perspektiividest,” In: Eesti Teaduste Akadeemia Seminari Materjalid, Teaduse uued suunad, Materjaliteadus, Eesti Teaduste Akadeemia, Tallinn, pp. 23-30, 2004. 72. P. Adamson, “Reflection characteristics of nanoscopic layered structures and optical diagnostics of ultrathin dielectric films,” In: Proc. 2003 Third IEEE Conference on Nanotechnology. IEEENANO 2003 (Cat. No.03TH8700). Piscataway, NJ, USA, IEEE, 2, pp. 836–839, 2003. 73. P. Adamson, “Optical diagnostics of nanometer dielectric films by combining ellipsometry and differential reflectance,” In: Physics, Chemistry and Application of Nanostructures (Eds. V. E. Borisenko, Publications • 135 74. 75. 76. 77. 78. 79. 80. 81. S. V. Gaponenko, and V. S. Gurin), World Scientific, Singapore, pp. 96–99, 2003. P. Adamson, “Optical probing of nanoscopic insulating layered structures via differential characteristics of specular reflection of light ,” In: IEEE Proc. 2004 International Conference on MEMS, NANO and Smart Systems (Cat. #P2189). USA, IEEE, pp. 535–541, 2004. M. Agåker, J. Söderström, T. Käämbre, C. Glover, L. Gridneva, T. Schmitt, A. Augustsson, M. Mattesini, R. Ahuja, J. E. Rubensson, “Resonant inelastic soft X-ray scattering at hollow lithium states in solids,” In: Program and Abstracts, The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, pp. 37, 2004. A. Agui, S. Butorin, T. Käämbre, C. Såthe, T. Saitoh, Y. Moritomo, J. Nordgren, “Resonant O Ka Emission Spectroscopy of double layered Manganite La1.2Sr1.8Mn2O7,” In: Program and Abstracts, The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, pp. 96, 2004. V. Fedossejev, “A new nonspecular effect in reflection of a light beam carrying orbital angular momentum,” In: Biannual Report 2002/2003, Institute of Physics, University of Tartu, ISSN 1406–7927, Tartu, pp. 40–43, 2004. E. Feldbach, I. Kudryavtseva, A. Lushchik, Ch. Lushchik, I. Martinson, V. Nagirnyi, E. Vasil’chenko, “Creation and transformation of defects by VUV radiation in LiF single crystals,” In: MAX-LAB Activity Report 2003, National Laboratory, Lund, Sweden, pp. 124– 125, 2004. A. Freiberg, “What is the bandwidth of excitons in photosynthetic antenna nanoaggregates,” Biannual Report 2002/2003, Institute of Physics, University of Tartu, ISSN 1406–7927, Tartu, pp. 51–53, 2004. C. Glover, M. Agåker, T. Käämbre, T. Schmitt, M. Adell, L. Ilver, J. Kanski, L. Kjeldgaard, J. E. Rubensson, “Localized 3d excitations in Ge, GaAs, and GaN, populated in inelastic soft X-ray scattering, resonantly enhanced at the 3p edges,” In: Program and Abstracts, The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, pp. 119, 2004. C. Glover, T. Käämbre, M. Agaker, L. Gridneva, T. Balasubramanian, J. Andersen, J. E. Rubensson, “Effects of momentum conservation in 136 • Biannual Report 2004/2005 82. 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. resonant inelastic soft X-ray scattering in the bulk and at the surface of Be metal,” In: Program and Abstracts, The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, pp. 232, 2004. M. Haas, “Coherent resonant scattering of synchrotron radiation in randomly oriented paramagnetic and diamagnetic biomolecular 57Fe complexes,” In: Biannual Report 2002/2003, Institute of Physics, University of Tartu, ISSN 1406–7927, Tartu, pp. 30–35, 2004. R. Jaaniso, “Milline oli aasta 2003 füüsikas ja Eesti füüsikas?” In: Eesti Füüsika Seltsi Aastaraamat 2003, Tartu, pp. 5–8, 2004. A. Kikas, T. Käämbre, A. Saar, K. Kooser, E. Nõmmiste, I. Martinson, “Resonant Inelastic X-ray Scattering at the K edge of oxygen and fuorine in insulators,” In: Program and Abstracts, The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, pp. 231, 2004. A. Kikas, “Röntgenkiirguse Ramani hajumine,” In: Eesti Füüsika Seltsi aastaraamat 2003, Tartu, Eesti, pp. 50, 2004. V. Kisand, E. Nõmmiste, E. Kukk, A. Caló, H. Aksela, S. Aksela, “Photoexcitation, photoionisation and photofragmentation of molecular rubidium halides,” In: MAX-LAB Activity Report 2003, National Laboratory, Lund, Sweden, pp. 126–127, 2004. A. Kotlov, S. Dolgov, L. Jönsson, A. Lushchik, V. Nagirnyi, G. Svensson, B. I. Zadneprovski, “Excitonic and recombination luminescence of Al2(WO4)3 crystals,” In: MAX-LAB Activity Report 2003, National Laboratory, Lund, Sweden, pp. 128–129, 2004. N. Kristoffel, P. Rubin, “Kupraatülijuhtide energeetilised karakteristikud ja nende seosed dopeeringskaalal,” In: Eesti Füüsika Seltsi aastaraamat 2003, Tartu, pp. 50–51, 2004. N. Kristoffel, P. Rubin, “Two-component scenario and related gaps in cuprates,” cond-mat/0408574, pp. 1–14, 2004. N. Kristoffel, T. Örd, “Magneesiumdiboriidi ülijuhtivuse mehhanism,” In: Eesti Vabariigi Teaduspreemiad, pp. 26–35, 2004. N. Kristoffel, T. Örd, “Magnesium diboride superconductivity,” In: Biannual Report 2002/2003, FI, TÜ, pp. 35–40, 2004. E. Kukk, M. Huttula, J. Rius i Riu, H. Aksela, S. Aksela, R. Ruus, “VUV-induced processes in alkali halide dimer molecules – how well does the ionic approach work?” In: Program and Abstracts, The 14th Publications • 137 93. 94. 95. 96. 97. 98. 99. 100. 101. 102. Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, pp. 54, 2004. P. Kuusk, M. Saal, “Advances in string and brane cosmology,” In: Biannual Report 2002/2003, Institute of Physics, University of Tartu, ISSN 1406–7927, Tartu, pp. 44–47, 2004. P. Kuusk, “Eesõna,” In: Eesti Füüsika Seltsi aastaraamat 2003, Tartu, pp. 3, 2004. H. Käämbre, H. Jõgi (compilers), “Biannual Report 2002/2003, Inst. of Physics, Univ. of Tartu,” In: , Tartu, Estonia, pp. 1–205, 2004. H. Käämbre (compiler), “Institute of Physics of the University of Tartu,” In: Centres of Excellence of Estonian Science, Association of the Centres of Excellence of Estonian Science, Tallinn, Estonia, pp. 77–92, 2004. E. Nõmmiste, V. Kisand, M. Valden, M. Hirsimäki, E. Kukk, T. Käämbre R. Ruus, A. Kikas, “Studing KF monolayers on copper substrate,” In: Book of Abstracts, Fifth Nordic Conf. on Surface Science, Tampere, Finland, pp. 57, 2004. E. Nõmmiste, V. Kisand, E. Kukk, A. Calo, H. Aksela, S. Aksela, “Photoexcitation, -ionization and fragmentation of molecular rubidium halides,” In: Program and Abstracts, The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, pp. 133, 2004. V. Peet, “Mittegaussilised laserkimbud mittelineaarses optikas,” In: Eesti Füüsika Seltsi aastaraamat 2003, Tartu, pp. 13–27, 2004. A. V. Pokropivny, R. Lõhmus, D. Erts, I. Hussainova, H. Olin, A. Lõhmus, “Transformations of gold nanocontacts studied by molecular dynamics simulations,” In: Proceedings of NANOTECH 2004 Intern. Conf. on Nanotechnology, Boston, USA, pp. 1–5, 2004. D. E. Rakhimov, F. A. Savikhin, A. Ch. Lushchik, “Intrinsic emissions in alkali metal sulphates,” In: Proc. Intern. Conf. on Physico-Chemical Processes in Inorganic Materials, Kemerovo, Russia, 1, pp. 80–81, 2004. R. Rammula, J. Aarik, A. Kikas, T. Käämbre, V. Sammelselg, “AFM and XPS studies of ultrathin HfO2 films prepared by ALD,” In: Proc. 5th Nordic-Baltic Scanning Probe Microscopy Workshop, 16–19 June, 2004, Trondheim, Norway (Eds. Th. Tybell, A. Borg), Visual Knowledge AS, Trondheim, pp. 93–95, 2004. 138 • Biannual Report 2004/2005 103. E. Realo, K. Realo, “Natural radionuclides in radium-rich soils in North-East Estonia,” In: The Natural Radiation Environment VII. Book Series “Radioactivity in the Environment”. Simopoulos et al (Eds.). ISBN: 0-08-044137-8, Elsevier, London, pp. 00–00, 2004. 104. K. Realo, R. Koch, M. Lust, A. Uljas, E. Realo , “Lead-210 in air and surface soil in NE Estonia,” In: Full Papers of IRPA-11, 11th Int. Congress of International Radiation Protection Association, 23–28 May 2004, Madrid, CD-ROM ja http://www.irpa11.com, SRPC, Spain, 6a, No. 56, pp. 1–8, 2004. 105. V. Sammelselg, J. Aarik, A. Kikas, R. Rammula, T. Käämbre, K. Kooser, A. Zakharov, I. Martinson, “Study of growth process of ultrathin hafnia films,” In: MAX-LAB Activity Report 2003, National Laboratory, Lund, Sweden, pp. 84–85, 2004. 106. J. Takahashi, A. Suisalu, An. Kuznetsov, A. Laisaar, V. Hizhnyakov, J. Kikas, “Effect of hydrostatic pressure on irreversible thermal transformations in a polymer glass at low temperatures,” http://arXiv.org/abs/cond-mat/0401345, pp. 1–28, 2004. POPULAR SCIENTIFIC ARTICLES, PUBLICISM 2004 107. J. L. Birman, A. A. Maradudin, R. Pick, K. K. Rebane, “Ija Pavlovna Ipatova,” Physics Today, No. 8, pp. 69–70, 2004. 108. R. Koch, “Tartu rahu 84. aastapäeval,” Ajaleht “Rahvuslik Koguja”, Tartu, Eesti, No. 1 (34), pp. 1, 2004. 109. P. Kuusk, “Bernard Bolzano ja matemaatika põhialused,” Akadeemia, 16, pp. 592–632, 2004. 110. P. Kuusk, “Bernard Bolzano “Lisandusi matemaatika põhjendatuma esituse juurde” (valikuline tõlge),” Akadeemia, 16, pp. 567–591, 2004. 111. P. Kuusk, “Kihlveod mustade ja valgete aukude ümber,” Horisont, No. 5, pp. 40–43, 2004. 112. P. Kuusk, “Luhta-mineku lugemise luhtaminek,” In: Püsimatu metaphysicus. Madis Kõiv 75, EYS Veljesto Kirjastus, Tartu, pp. 54–76, 2004. 113. P. Kuusk, “Termiitide elu,” In: Püsimatu metaphysicus. Madis Kõiv 75, EYS Veljesto Kirjastus, Tartu, pp. 16–17, 2004. Publications • 139 114. T. Kärner, “Eesti rahvastiku hetkeseis ja tulevikuväljavaated,” Sirp, No. 24, pp. 3–4, 2004. 115. H. Käämbre (koostaja), “Tartu Ülikooli Füüsika Instituut,” In: Eesti teaduste tippkeskused, Eesti Teaduse tippkeskuste Ühendus, Tallinn, Eesti, pp. 75–88, 2004. 116. H. Käämbre, “Renessansiaja inimene meie keskel (Madis Kõivu 75. sünnipäevaks),” Maaleht, 2 dets., pp. 20, 2004. 117. H. Käämbre, “Emakeel argi- ja teaduskeelena,” Õpetajate Leht, 30. apr., pp. 6, 2004. 118. T. Kööp, M. Lust, R. Rajamäe, E. Realo, E. Tanner jt , “Eelnõu. Väljaarvamistasemete tuletamise alused ja radionukliidide väljaarvamistasemed. Vabariigi Valitsuse 30. aprilli 2003. a. määrus nr 163,” In: RTL, 04.05.2004, Tallinn, Eesti, 39, No. 265, 2004. 119. Ch. Lushchik, “Elutööst,” In: Eesti Vabariigi Teaduspreemiad, Eesti Teaduste Akadeemia, pp. 10–19, 2004. 120. E. Realo, T. Kööp, M. Lust, R. Rajamäe, E. Tanner jt, “Eelnõu. Kvalifitseeritud kiirguseksperdi litsentsi ja selle taotluse vorm ning litsentsi andmise, pikendamise, peatamise ja kehtetuks tunnistamise kord. Keskkonnaministri 12. oktoobri 2004. a määrus nr 127,” In: RTL, 19.10.2004, Tallinn, Eesti, 134, No. 2077, 2004. 121. K. Rebane, “Kuidas saada stressi ja riskita üle Ringtee,” Tartu Postimees, pp. 23.01., 2004. 122. K. Rebane, “Õige on atra seada,” Postimees, pp. 08.03., 2004. 123. K. Rebane, “Ajalugu muuta pole aus,” Postimees, pp. 17.09., 2004. 124. K. Rebane, “Aga tagastatud varal lasunud võlakoorem?” Äripäev, pp. 28.09., 2004. 125. K. Rebane, “Olgem valvsad: radioaktiivne terrorism,” Äripäev, pp. 03.12., 2004. 126. E. Tanner, T. Kööp, M. Lust, S. Nazarenko, R. Rajamäe, H. Putnik, E. Realo jt , “Eelnõu. Kiirgusseadus. Vastu võetud 24. märtsil 2004.,” RTL, 16.04.2004, Tallinn, Eesti, 26, No. 173, 2004. BOOKS 2004 127. A. Aret, P. Kuusk (toimetajad), “Eesti Füüsika Seltsi aastaraamat 2003,” Tartu, pp. 112, 2004. 140 • Biannual Report 2004/2005 128. R. Koch (kaastõlkija), “Õpilase teadusentsüklopeedia (tõlge inglise keelest The Concise Science Encyclopedia) ,” Varrak, Tallinn, pp. 320, 2004 . 129. H. Käämbre (translator), “Astronomy & Space, Communications, Physics, Transport,” Philip`s Science & Technology, Eesti Entsüklopeediakirjastuse AS, Tallinn, Eesti, pp. 1–318, 2004. PAPERS 2005 130. R. Aceves, T. M. Piters, S. Zazubovich, “Luminescence of excitons and Eu2+ vc centres in KI:Eu2+,” Phys. stat. sol. (b), 242, pp. 2121–2128, 2005. 131. P. Adamson, “Scanning angle differential reflectometry around the Brewster angle to probe ultrathin dielectric films,” Thin Solid Films, 492, pp. 221–225, 2005. 132. P. Adamson, “Reflection of light in the vicinity of of the Brewster angel from a multilayer system of ultrathin inhomogeneous dielectric films ,” J. Modern Opt., 52, pp. 1457–1469, 2005. 133. ȼ. Ɇ. Ⱥɝɪɚɧɨɜɢɱ, Ɇ. Ⱥ. Ȼɨɥɶɲɨɜ, ɘ. Ƚ. ȼɚɣɧɟɪ, ȿ. Ⱥ. ȼɢɧɨɝɪɚɞɨɜ, Ƚ. ɇ. ɀɢɠɢɧ, ȼ. Ƚ. Ʉɨɥɨɲɧɢɤɨɜ, Ɉ. ɇ. Ʉɨɦɩɚɧɟɰ, Ɉ. ɇ. Ʉɨɪɨɬɚɟɜ, ɘ. ȿ. Ʌɨɡɨɜɢɤ, ȼ. ɋ. Ʌɟɬɨɯɨɜ, Ȼ. ɇ. Ɇɚɜɪɢɧ, Ɇ. ɇ. ɉɨɩɨɜɚ, Ʉ. Ʉ. Ɋɟɛɚɧɟ, Ⱥ. ɂ. Ɋɵɫɤɢɧ, ȿ. Ⱥ. Ɋɹɛɨɜ, Ȼ. Ɇ. ɏɚɪɥɚɦɨɜ, “ɉɚɦɹɬɢ Ɋɨɦɚɧɚ ɂɜɚɧɨɜɢɱɚ ɉɟɪɫɨɧɨ (04.01.1932 – 17.01.2002),” Ɉɩɬ. ɫɩɟɤɬɪɨɫɤ., 98, No. 5, pp. 710–715, 2005. 134. A. Agui, T. Käämbre, C. Såthe, J. Nordgren, M. Usuda, T. Saitoh, Y. Morimoto, “Resonant O K emission spectroscopy of layered manganate La1.2Sr1.8Mn2O7,” J. Electron Spectrosc. Relat. Phenom., 144–147, pp. 589–592, 2005. 135. M. Aunapuu, K. Kurrikoff, H. Tamm, A. Adojaan, T. Järveots, T. Suuroja, S. Kõks, E. Vasar, K. Saal, A. Arend, “Morphological investigation of transgenic with CCK2 receptor over-expression mice brain. A pilot study,” Eesti Arst, Lisa 6, pp. 30–33, 2005. 136. V. Babin, K. Blazek, A. Krasnikov, K. Nejezchleb, M. Nikl, T. Savikhina, S. Zazubovich, “Luminescence of undoped LuAG and YAG crystals,” Phys. stat. sol. (c), 2, No. 1, pp. 97–100, 2005. Publications • 141 137. G. Benedek, V. Hizhnyakov, “The role of defect-induced phonon localization in quantum diffusion,” Phys. stat. sol. (c), 2, pp. 495–498, 2005. 138. K. Blazek, A. Krasnikov, K. Nejezchleb, M. Nikl, T. Savikhina, S. Zazubovich, “Luminescence and defects creation in Ce3+-doped YAlO3 and LuYAlO3 crystals,” Phys. stat. sol. (b), 242, pp. 1315– 1323, 2005. 139. P. Bohacek, P. Fabeni, A. Krasnikov, M. Nikl, G. P. Pazzi, C. Susini, S. Zazubovich, “Defects in UV-irradiated PbWO4:Mo crystals monitored by TSL measurements,” Phys. stat. sol. (c), 2, No. 1, pp. 547– 550, 2005. 140. Y. Chen, B. Liu, C. Shi, M. Kirm, M. True, S. Vielhauer, G. Zimmerer, “Luminescent properties of Gd2SiO3 powder crystal doped with Eu3– under VUV-UV excitation,” J. Phys.: Condens. Matter, 17, pp. 1217–1224, 2005. 141. S. Dolgov, E. Feldbach, A. Kärkkänen, T. Kärner, P. Liblik, A. Maaroos, S. Nakonechnyi, “Low-temperature (4–295 K) thermoluminescence of pure and doped MgO and CaO single crystals,” Phys. stat. sol. (c), 2, No. 1, pp. 422–425, 2005. 142. S. Dueñas, H. Castán, H. Carc a, J. Barbolla, K. Kukli, J. Aarik, M. Ritala, M. Leskelä, “Electrical characterization of hafnium oxide and hafnium-rich silicate films grown by atomic layer deposition ,” Microelectronics Reliability, 45, pp. 949–952, 2005. 143. S. Dueñas, H. Castán, H. Carcía, E. San Andrés, M. Toledano-Loque, I. Márttil, G. González-Díaz, K. Kukli, T. Uustare, J. Aarik, “A comparative study of the electrical properties of TiO2 films grown by high-pressure reactive sputtering and atomic layer deposition,” Semicond. Sci. Technol., 20, No. 10, pp. 1044–1051, 2005. 144. R. Hellborg, M. Kiisk, P. Persson, G. K. Stenström, “Vacuum in an accelerator system – calculations and measurements,” Vacuum, Elsevier, London, 78, No. 2, pp. 427–434, 2005. 145. V. Hizhnyakov, G. Benedek, “Quantum diffusion: effect of defectlocalized phonon dynamics,” Eur. J. Phys B, 43, pp. 431–438, 2005. 146. V. Hizhnyakov, H. Kaasik, “Emission of dielectric with oscillating refractive index,” J. Phys. C, 21 , pp. 155–160, 2005. 142 • Biannual Report 2004/2005 147. V. Hizhnyakov, V. Boltrushko, H. Kaasik, A. Shelkan, “Multiphonon processes in impurity centres: nonperturbative theory,” Phys. stat. sol. (a), 202, pp. 228–234, 2005. 148. V. Hizhnyakov, V. Boltrushko, I. Tehver, “Optical transitions in the centres with soft dynamics in the final state,” J. Phys.: Conf. Ser., 21, pp. 161–166, 2005. 149. V. Issahanyan, T. Kärner, A. Maaroos, S. Nakonechnyi, “Spin relaxation processes in the defect hole centres of Be doped MgO single crystals,” Phys. stat. sol. (c), 2, No. 1, pp. 426–429, 2005. 150. V. Y. Ivanov, V. A. Pustovarov, M. Kirm, E. S. Shlygin, K. I. Shirinskii, “Energy transfer in Gd2SiO5–Ce, Y2SiO5–Ce, Be2La2O5–Ce under selective VUV- and core excitation,” Phys. Solid State, 47, pp. 1435– 1439, 2005. 151. K. V. Ivanovskikh, V. A. Pustovarov, B. V. Shulgin, M. Kirm, “Lowtemperature time-resolved luminescence VUV-spectroscopy of SrF2:Er crystals,” Phys. Solid State, 47, pp. 1395–1397, 2005. 152. V. Jacobsen, T. Tätte, R. Branscheid, U. Maeorg, K. Saal, I. Kink, A. Lõhmus, M. Kreiter, “Electrically conductive and optically transparent Sb-doped SnO2 STM-probe for local excitation of electroluminescence,” Ultramicroscopy, 104, No. 1, pp. 39–45, 2005. 153. T. Jantson, T. Avarmaa, H. Mändar, T. Uustare, R. Jaaniso, “Nanocrystalline Cr2O3-TiO2 thin films by pulsed laser deposition ,” Sens. Actuators B, 109, pp. 24–31, 2005. 154. K. Jõgar, L. Metspalu, K. Hiiesaar, A. Luik, A.-J. Martin, M. Mänd, R. Jaaniso, A. Kuusik, “Physiology of diapause in pupae of Pieris brassicae L. (Lepidoptera: Pieridae),” Agronomy Research, 3, pp. 21–37, 2005. 155. V. Kiisk, I. Sildos, S. Lange, V. Reedo, T. Tätte, M. Kirm, J. Aarik, “Photoluminescence characterization of pure and Sm3+–doped thin metaloxide films,” Appl. Surf. Sci., 247, No. 1–4, pp. 412–417, 2005. 156. A. Kikas, T. Käämbre, V. Kisand, A. Saar, K. Kooser, E. Nõmmiste, I. Martinson, “Resonant inelastic X-ray scattering at the K edge of oxygen and fluorine in insulators,” J. Electron Spectrosc. Relat. Phenom., 144–147, pp. 845–848, 2005. 157. A. Kikas, V. Kisand, T. Käämbre, R. Ruus, E. Nõmmiste, M. Hirsimäki, M. Valden, E. Kukk, H. Aksela, S. Aksela, “Insulating properties Publications • 143 158. 159. 160. 161. 162. 163. 164. 165. 166. 167. of ultrathin KF layers on Cu(100): Resonant Auger spectroscopy,” Surface Science, 584, pp. 49–54, 2005. J. Kikas, A. Suisalu, An. Kuznetsov, A. Laisaar, J. Takahashi, V. Hiznyakov, “Pressure effects on relaxation in a polymer glass: A persistent spectral hole burning study,” Opt. Spectr., 98, No. 5, pp. 738–744, 2005. M. Kirm, J. Aarik, M. Jürgens, I. Sildos, “Thin films of HfO2 and ZrO2 as potential scintillators,” Nucl. Instr. Meth. Phys. Res. A, 537, No. 5, pp. 251–255, 2005. M. Kirm, A. Andrejczuk, J. Krzywinski, R. Sobierajski, “Influence of excitation density on luminescence decay in Y3Al5O12:Ce and BaF2 crystals excited by free electron laser radiation in VUV,” Phys. stat. sol. (c), 2, pp. 649–652, 2005. M. Kirm, Y. Chen, S. Neicheva, K. Shimamura, N. Shiran, M. True, S. Vielhauer, “VUV spectroscopy of Eu doped LiCaAlF6 and LiSrAlF6 crystals,” Phys. stat. sol (c), 2, pp. 418–421, 2005. M. Kirm, A. Lushchik, Ch. Lushchik, “Creation of groups of spatially correlated excitations in wide-gap solids,” Phys. stat. sol. (a), 202, No. 2, pp. 213–220, 2005. M. Kirm, V. N. Makhov, M. True, S. Vielhauer, G. Zimmerer, “VUV-luminescence and excitation spectra of the heavy trivalent rare earth ions in fluoride matrices,” Phys. Solid State, 47, pp. 1368–1375, 2005. V. Kisand, E. Nõmmiste, E. Kukk, A. Caló, H. Aksela, S. Aksela, “Photoexcitation, photoionisation and photofragmentation of molecular rubidium halides,” J. Electron Spectrosc. Relat. Phenom., 144– 147, pp. 175–178, 2005. L. Kjeldgaard, T. Käämbre, J. Schiessling, I. Marenne, J. N. O'Shea, J. Schnadt, C. J. Glover, M. Nagasono, D. Nordlund, M. G. Garnier, L. Qian, J.-E. Rubensson, P. Rudolf, N. Mårtensson, J. Nordgren, P. A. Brühwiler, “Intramolecular vibronic dynamics in molecular solids: C60,” Phys. Rev. B, 72, No. 20, pp. 205414-1-4, 2005. L. Kommel, I. Hussainova, O. Volobueva, R. Lõhmus, “Microstructural evolution and mechanical properties of nanostructured copper,” Proc. Est. Acad. Sci. Engineering, 11 , No. 3, pp. 187–197, 2005. P. Konsin, B. Sorkin, “Off-center displacements of Ti ions in oxide ferroelectrics and a gigantic photo-induced dielectric constant of 144 • Biannual Report 2004/2005 168. 169. 170. 171. 172. 173. 174. 175. 176. 177. 178. quantum paraelectric perovskite oxides in the electron-lattice theory,” J. Physics: Conf. Series, 21, pp. 167–172, 2005. P. Konsin, B. Sorkin, “A gigantic photoinduced dielectric constant of quantum paraelectric perovskite oxides under a weak electric field in the electron-lattice theory,” Ferroelectrics, 320, pp. 69–74, 2005. P. Konsin, B. Sorkin, “Generalized multiple gap model for the superconductivity in MgB2,” J. Supercond., DOI:10.1007/s10948-0050062-6, 2005. M. M. Korshunov, S. G. Ovchinnikov, A. V. Sherman, “Spinfluctuations and spin-exciton mechanisms of superconductivity in cuprates,” The Physics of Metals and Metallography, 100, No. Suppl. 1, pp. S75–S78, 2005. M. M. Korshunov, S. G. Ovchinnikov, A. V. Sherman, “Effective Hamiltonian and the properties of normal and superconducting phases of n-type cuprates,” Physica B, 359–361, pp. 521–523, 2005. A. Kotlov, S. Dolgov, E. Feldbach, L. Jönsson, M. Kirm, A. Lushchik, V. Nagirnyi, G. Svensson, B. I. Zadneprovski, “Exciton and recombination luminescence of Al2(WO4)3 crystals,” Phys. stat. sol. (c), 2, No. 1, pp. 61–64, 2005. V. Krasnenko, A. H. Tkaczyk, E. R. Tkaczyk, Ö. Farkas, K. Mauring, “Vibrations-determined properties of green fluorescent protein,” Biopolymers, 78, No. 3, pp. 140–146, 2005. A. Krasnikov, T. Savikhina, S. Zazubovich, M. Nikl, J. A. Mares, K. Blazek, K. Nejezchleb, “Luminescence and defects creation in Ce3+-doped aluminium and lutetium perovskites and garnets,” Nucl. Instr. Meth. Phys. Res. A, 537, pp. 130–133, 2005. A. Krasnikov, M. Nikl, A. Stolovits, Y. Usuki, S. Zazubovich, “Luminescence of the PbWO4:5 % Cd crystal,” Phys. stat. sol. (c), 2, pp. 77– 80, 2005. N. Kristoffel, P. Rubin, “Effect of photodoping on cuprate superconductivity,” Physica C, 418, pp. 49–52, 2005. N. Kristoffel, P. Rubin, “Two-component scenario, cuprate related gaps, and superconducting density,” Proc. Estonian Acad. Sci. Phys. Mat., 54, No. 2, pp. 98–110, 2005. N. Kristoffel, P. Rubin, “Cuprate interband superconducting density for doping driven spectral overlaps,” J. Superconductivity, DOI: 10.1007/s10948-005-0063-5, 2005. Publications • 145 179. D. Kropman, T. Kärner, U. Abru, Ü. Ugaste, E. Mellikov, “Interaction between point defects, extended defects and impurities in the Si-SiO2 system during the process of its formation,” Mater. Sci. Engineering B, 114–115, pp. 295–298, 2004. 180. K. Kukli, J. Aarik, T. Uustare, J. Lu, M. Ritala, A. Aidla, L. Pung, A. Hårsta, M. Leskelä, A. Kikas, V. Sammelselg, “Engineering structure and properties of hafnium oxide films by atomic layer deposition temperature,” Thin solid Films, 479, pp. 1–11, 2005. 181. K. Kukli, M. Ritala, T. Pilvi, T. Aaltonen, J. Aarik, M. Lautala, M. Leskelä, “Atomic layer deposition rate, phase composition and performance of HfO2 films on noble metal and alkoxylated silicon substrates,” Mater. Sci. Engeneering B , 118, pp. 112–116, 2005. 182. K. Kukli, T. Aaltonen, J. Aarik, J. Lu, M. Ritala, S. Ferrari, A. Hårsta, M. Leskelä, “Atomic layer deposition and characterization of HfO2 films on noble metal film substrates ,” J. Electrochem. Soc., 152, pp. F75–F82, 2005. 183. S. Lange, I. Sildos, V. Kiisk, M. Kirm, “Photoluminescence of RE-doped thin metal-oxide films,” Phys. stat. sol. (c), 2, No. 1, pp. 326–329, 2005. 184. J. Lu, J. Aarik, J. Sundqvist, K. Kukli, A. Hårsta, J.-O. Carlsson, “Analytical TEM characterization of the interfacial layer between ALD HfO2 film and silicon substrate,” J. Cryst. Growth, 273, pp. 510–514, 2005. 185. A. Lushchik, M. Kirm, I. Kudryavtseva, Ch. Lushchik, I. Martinson, V. Nagirnyi, E. Vasil’chenko, “Multiplication of electronic excitations and prospects for the increasing of scintillation efficiency in wide-gap crystals,” Nucl. Instr. Meth. Phys. Res. A, 537, No. 1–2, pp. 45–49, 2005. 186. K. Mauring, J. Deich, F.I. Rosell, T.B. McAnaney, W.E. Moerner, S.G. Boxer, “Enhancement of the fluorescence of the blue fluorescent proteins by high pressure or low temperature,” J. Phys. Chem. B, 109, No. 26, pp. 12976–12981, 2005. 187. N. Mironova-Ulmane, V. Skvortsova, A. Kuzmin, U. Ulmanis, I. Sildos, E. Cazzanelli, G. Mariotto, “Magnetic ions exchange interactions in NiO-MgO solid solutions,” Phys. Solid State, 47, pp. 1516–1522, 2005. 146 • Biannual Report 2004/2005 188. V. Nagirnyi, A. Kotlov, L. Jönsson, M. Kirm, A. Lushchik, “Emission decay kinetics in a CaWO4:Bi crystal,” Nucl. Instr. Meth. Phys. Res. A, 537, No. 1–2, pp. 61–65, 2005. 189. M. Nikl, H. Ogino, A. Krasnikov, A. Beitlerova, A. Yoshikawa, T. Fukuda, “Photo- and radioluminescence of Pr-doped Lu3Al5O12 single crystal,” Phys. stat. sol. (a), 202, pp. R4–R6, 2005. 190. I. N. Ogorodnikov, V. A. Pustovarov, M. Kirm, V. S. Cheremnykh, “A time-resolved luminescence spectroscopy study of self-trapped excitons in NH4H2PO4 crystals,” J. Lumin., 115, pp. 69–76, 2005. 191. V. Pankratov, M. Kirm, H. von Seggern, “Intrinsic luminescence in yttrium trifluoride,” J. Lumin., 113, pp. 143–150, 2005. 192. V. Pankratov, H. von Seggern, M. Kirm, “Excitonic luminescence and defect formation in yttrium fluoride,” Phys. stat. sol. (c), 2, pp. 371– 374, 2005. 193. V. Peet, S. Shchemeljov, “Sum-frequency generation and multiphoton ionization in spatially incoherent conical laser beams,” Opt. Commun., 246, pp. 451–463, 2005. 194. H. Pettai, V. Oja, A. Freiberg, A. Laisk, “Photosynthetic activity of far-red light in green plants,” Biochem. Biophys. Acta, 1708, pp. 311– 321, 2005. 195. H. Pettai, V. Oja, A. Freiberg, A. Laisk, “The long-wavelength limit of plant photosynthesis,” FEBS Lett., 579, pp. 4017–4019, 2005. 196. E. Radzhabov, M. Kirm, “Triplet luminescence of cadmium centres in alkaline-earth fluoride crystals,” J. Phys.: Condens. Matter, 17, pp. 5821–5830, 2005. 197. E. Realo, K. Realo, “Natural radionuclides in radium-rich soils in North-East Estonia,” J.P.McLaughlin, S.E. Simopoulos, F.Steinhäusler (Eds.). The Natural Radiation Environment VII. Seventh Intern. Symposium on the Natural Radiation Environment (NRE-VII), 20–24 May 2002, Rhodes, Greece. Book Series “Radioactivity in the Environment”, vol. 7. ISBN: 0-08-044137-8, Elsevier, Amsterdam, pp. 140–149, 2005. 198. A. Rebane, M. Drobizhev, M. Kruk, A. Karotki, I. Tehver, M. Scully , “Femtosecond resonance enhanced CARS for background-free detection of organic molecules,” J. Modern Optics, 52, pp. 1243– 1253, 2005. Publications • 147 199. Ʉ. Ʉ. Ɋɟɛɚɧɟ, “ɍɩɪɚɜɥɹɟɦɨɟ ɭɲɢɪɟɧɢɟ ɛɟɫɮɨɧɨɧɧɵɯ ɥɢɧɢɣ ɫ ɩɨɦɨɳɶɸ ɷɮɮɟɤɬɚ Ⱦɨɩɩɥɟɪɚ ɢ ɩɟɪɫɩɟɤɬɢɜɵ ɢɫɩɨɥɶɡɨɜɚɧɢɹ ɜ ɨɩɬɢɱɟɫɤɨɣ ɢɧɮɨɪɦɚɬɢɤɟ ɜɵɠɢɝɚɧɢɹ ɫɩɟɤɬɪɚɥɶɧɵɯ ɩɪɨɜɚɥɨɜ,” Ɉɩɬ. ɫɩɟɤɬɪɨɫɤ., 98, No. 5, pp. 845–849, 2005. 200. K. K. Rebane, “Purely electronic zero-phonon lines in optical data storage and processing,” Physical Chemistry, Chemical Physics (PCCP), 7, No. 5, pp. 723–727, 2005. 201. I. Renge, “Lennard-Jones approach to optical zero-phonon spectra in impurities in glasses,” Chem. Phys. Lett., 405, No. 4–6, pp. 404–409, 2005. 202. P. Rubin, A. Sherman, “Magnetic properties of the two-dimensional Heisenberg model on a triangular lattice,” Phys. Lett. A, 334, No. 4, pp. 312–316, 2005. 203. R. Ruus, K. Kooser, E. Nõmmiste, A. Saar, I. Martinson, A. Kikas, “Cs 3d absorption and resonant photoemission study of caesium halogenides,” Physica Scripta, T115, pp. 396–398, 2005. 204. R. Ruus, E. Kukk, M. Huttula, H. Aksela, S. Aksela, “Resonant VUV absorption in CsCl monomers and dimers – experiment and theory,” J. Electron Spectrosc. Relat. Phenom., 144–147, pp. 1215–1218, 2005. 205. M. Rätsep, C. N. Hunter, J. D. Olsen, A. Freiberg, “Band structure and local dynamics of excitons in bacterial light-harvesting complexes revealed by spectrally selective spectroscopy,” Photosynth. Res., 86, pp. 37–48, 2005. 206. P. Saari, M. Menert, H. Valtna, “Photon localization barrier can be overcome,” Opt. Commun., 246, No. 4–6, pp. 445–450, 2005. 207. F. A. Savikhin, A. Kasikov, “A new look at the formation of old believer communities in the Western Prichud’e of Estonia (on the Basis of Historical and Linguistic Data),” Russian Linguistics, Springer, 29, No. 2, pp. 137–187, 2005. 208. F. Savikhin, M. Kerikmäe, E. Feldbach, A. Lushchik, D. Onishchik, D. Rakhimov, I.Tokbergenov, “Fast intrinsic emission with the participation of oxyanion and cation excitations in metal sulphates,” Phys. stat. sol. (c), 2, No. 1, pp. 252–255, 2005. 209. J. Schiessling, L. Kjeldgaard, T. Käämbre, I. Marenne, J. N. O'Shea, J. Schnadt, C. J. Glover, M. Nagasono, D. Nordlund, M. G. Garnier, L. Qian, J.-E. Rubensson, P. Rudolf, N. Mårtensson, J. Nordgren, 148 • Biannual Report 2004/2005 210. 211. 212. 213. 214. 215. 216. 217. 218. 219. P. A. Brühwiler, “Bulk and surface charge states of K3C60,” Phys. Rev. B, 71, No. 16, pp. 165420-1-16, 2005. D. Schiffbauer, C. Wickleder, G. Meyer, M. Kirm, M. Stephan, P. C. Schmidt, “Crystal structure, electronic structure and luminescence of Cs2KYF6:Pr3+,” Z. Anorg. Allg. Chem., 631, pp. 3046– 3052, 2005. A. Sherman, M. Schreiber, “Resonance peak and incommensurability in cuprate perovskites,” The Physics of Metals and Metallography, 100, No. Suppl. 1, pp. S86–S89, 2005. A. Sherman, “Magnetic properties of cuprate perovskites,” In: Proc. NATO ARW “Smart Materials for Ranging Systems”, Krasnoyarsk, Russia, 29 August – 1 September 2004, Kluwer 2005, pp. 115–128, 2005. A. Sherman, “Incommensurate magnetic response in cuprate perovskites,” Phys. Lett. A, 337, No. 4–6, pp. 435–440, 2005. A. Sherman, M. Schreiber, “Incommensurate spin dynamics in underdoped cuprate perovskites,” Intern. J. Modern Phys. B, 19, No. 13, pp. 2145–2159, 2005. A. Stolovits, A. Sherman, R. K. Kremer, Hj. Mattausch, H. Okudera, X-M. Ren, A. Simon, J. R. O’Brien, “Quantum interference of electrons in Nb5– Te4 single crystals,” Phys. Rev. B, 71, pp. 144519, 2005. T. Tamm, J. Linnanto, A. Ellervee, A. Freiberg, “Modeling of pressure effects on absorption spectra of solvated chlorophyll and bacteriochlorophyll molecules,” In: Lecture Series on Computer and Computational Sciences, Brill Academic Publishers, 3A, pp. 550–553, 2005. I. Tehver, “Transform relations for CARS excitation profiles,” Phys. stat. sol. (c): Conf. and Critical Reviews, 2, pp. 499–502, 2005. K. Timpmann, G. Trinkunas, P. Qian, C. N. Hunter, A. Freiberg, “Excitons in core LH1 antenna complexes of photosynthetic bacteria: Evidence for strong exciton coupling and off-diagonal disorder,” Chem. Phys. Lett., 414, pp. 359–363, 2005. S. N. Tkachev, M. H. Manghnani, A. Niilisk, J. Aarik, H. Mändar, “Raman and Brillouin scattering spectroscopy studies of atomic-layerdeposited ZrO2 and HfO2 thin films,” Spectrochimica Acta A, 61, pp. 2434–2438, 2005. Publications • 149 220. S. N. Tkachev, M. H. Manghnani, A. Niilisk, J. Aarik, H. Mändar, “Micro-Raman spectroscopy and X-ray diffraction studies of atomiclayer-deposited ZrO2 and HfO2 thin films,” J. Mater. Sci., 40, pp. 4293–4298, 2005. 221. G. Trinkunas, A. Freiberg, “Abrupt exciton self-trapping in finite and disordered one-dimensional aggregates,” J. Lumin., 112, pp. 420–423, 2005. 222. E. Vasil’chenko, I. Kudryavtseva, A. Lushchik, Ch. Lushchik, V. Nagirnyi, “Selective creation of colour centres and peaks of thermally stimulated luminescence by VUV photons in LiF single crystals,” Phys. stat. sol. (c), 2, No. 1, pp. 405–408, 2005. 223. A. Voloshinovskii, S. Zazubovich, G. Stryganyuk, I. Pashuk, “Luminescence of CsBr:Tl crystals under synchrotron excitation,” J. Lumin., 111, pp. 9–15, 2005. 224. K. Õige, T. Avarmaa, A. Suisalu, R. Jaaniso, “Effect of long-term aging on oxygen sensitivity of luminescent Pd-tetraphenylporphyrin/ PMMA films,” Sens. Acuators B, 106, pp. 424–430, 2005. PROCEEDINGS 2005 225. J. Aarik, A. Kasikov, M. Kirm, S. Lange, T. Uustare, H. Mändar, “Optical properties of crystalline Al2O3 thin films grown by atomic layer deposition,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 1–10 , 2005. 226. P. Adamson, “Characteristic reflection angles of nanoscopic layered media and optical probing dielectric films,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 336–345, 2005. 227. P. Adamson, “Reflection characteristics of nanoscopic anisotropic layered structures and optical diagnostics of nanofilms,” In: 5th IEEE Intern. Conf. on Nanotechnology (IEEE Cat No. 05TH8816) , IEEE, 1, pp. 255–258, 2005. 228. P. Adamson, “Long-wavelength approximation theory of light reflection from nanoscale media,” In: Technical Proc. 2005 NSTI Nanotechnology Conf. and Trade Show, NSTI, 3, pp. 664–667, 2005. 150 • Biannual Report 2004/2005 229. P. Adamson, “Differential reflection characteristics for optical probing of nanoscale anisotropic layered system,” In: Intern. Conf. on MEMS, NANO and Smart Systems, IEEE Comput. Soc., pp. 307–313, 2005. 230. V. Babin, K. Blazek, A. Krasnikov, K. Nejezchleb, M. Nikl, T. Savikhina, S. Zazubovich, “Intrinsic luminescence of LuAG and YAG crystals,” In: HASYLAB Activity Report 2004, DESY, Hamburg, Germany, pp. 271–272, 2005. 231. V. Babin, M. Kink, Y. Maksimov, K. Nejezchleb, M. Nikl, S. Zazubovich, “Antisite defects study in undoped and Ce3+-doped LuScAG and LuYAG crystals: influence of scintillating efficiency,” In: HASYLAB Activity Report 2005, DESY, Hamburg, Germany, Part I, pp. 261–262, 2005. 232. A. Calo, E. Kukk, S. Osmekhin, E. Nõmmiste, V. Kisand, M. Huttula, H. Aksela, S. Aksela, “The electronic decay of VUV excited resonant states of rubidium halides,” In: MAX-LAB Activity Report 2004, National Laboratory, Lund, Sweden, pp. 110–111, 2005. 233. G. Corradi, A. Kotlov, A. Lushchik, V. Nagirnyi, “3d10o3d94s and 3d10o3d94p electronic transitions in Li2B4O7:Cu single crystals,” In: HASYLAB Activity Report 2005, DESY, Hamburg, Germany, Part I, pp. 717–718, 2005. 234. S. Dolgov, E. Feldbach, A. Kotlov, I. Kudryavtseva, A. Lushchik, A. Maaroos, I. Martinson, V. Nagirnyi, E. Vasil’chenko, “Lowtemperature electron-hole processes in Li4SiO4 ceramics,” In: MAXLab Activity Report 2004, National Laboratory, Lund, Sweden, pp. 114–115, 2005. 235. E. Feldbach, A. Kotlov, L. Jönsson, M. Kirm, A. Lushchik, V. Nagirnyi, “Recombination luminescence of CaSO4 powders,” In: MAX-Lab Activity Report 2004, National Laboratory, Lund, Sweden, pp. 116–117, 2005. 236. E. Feldbach, M. Kirm, P. Liblik, A. Maaroos, H. Mändar, “Electronic excitations and luminescence in naturally nanoporous C12A7 compound,” In: HASYLAB Activity Report 2005, DESY, Hamburg, Germany, Part I, pp. 325–326, 2005. 237. V. Hizhnyakov, V. Boltrushko, “Anomalous optical spectra of centers with soft phonon dynamics in excited state,” In: Proc. SPIE - Optical Materials and Applications, 5946, pp. 192–201, 2005. Publications • 151 238. V. Ivanov, M. Kirm, V. Pustovarov, A. Kruzhalov, “Inner-shell excitation of intrinsic luminescence in oriented BeO crystals,” In: HASYLAB Activity Report 2005, DESY, Hamburg, Germany, Part I, pp. 669–670, 2005. 239. R. Jaaniso, T. Avarmaa, A. Suisalu, A. Floren, A. Ruudi, K. Õige, “Stability of luminescence decay parameters in oxygen sensitive polymer films doped with Pd-porphyrins,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 150–159, 2005. 240. E. Jalviste, N. Ohta, “Electric field induced reorientation of polar molecules in a poly(methyl methacrylate) film studied by electroabsorption spectroscopy,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 160–171, 2005. 241. I. Jõgi, J. Aarik, K. Kukli, H. Käämbre, M. Laan, J. Lu, T. Sajavaara, T. Uustare, “The effect of precursors on the structure and conductivity of atomic layer deposited TiO2 films,” Electrochem. Soc. Proc., 2005– 09, pp. 575–582, 2005. 242. A. Kikas, M. Valden, M. Hirsimäki, V. Kisand, K. Kooser, T. Käämbre, E. Nõmmiste, “Ultrathin films of KCl on Cu(100): photoelectron and resonant Auger Spectroscopy,” In: MAX-LAB Activity Report 2004, National Laboratory, Lund, Sweden, pp. 368– 369, 2005. 243. A. Kikas, T. Käämbre, V. Kisand, K. Kooser, E. Nõmmiste, V. Ivanov, V. Pustovarov, I. Martinson, “Resonantly excited X-ray fluorescence in BeO,” In: MAX-LAB Activity Report 2004, National Laboratory, Lund, Sweden, pp. 224–225, 2005. 244. M. Kirm, V. V. Harutunyan, V. N. Makhov, S. Vielhauer, “VUV luminescence of as-grown and electron irradiated corundum single crystals,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 41–46, 2005. 245. M. Kirm, A. Gektin, V. Nagirnyi, V. Nesterkina, K. Shimamura, N. Shiran, E. Villora, “VUV Spectroscopy of a Ca0,65Eu0,35F3,35 single crystal,” In: HASYLAB Activity Report 2005, DESY, Hamburg, Germany, Part I, pp. 569–570, 2005. 246. M. Kleemann, A. Suisalu, J. Kikas, “Polymer film doped with solvatochromic dye for humidity measurement,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 172–178, 2005. 152 • Biannual Report 2004/2005 247. N. Kristoffel, P. Rubin, “Dependence of the superconducting effective mass on doping in cuprates,” cond-mat/ 0506317, 2005. 248. N. Kristoffel, T. Örd, P. Rubin, “Cuprate interband model and doping dependence of the coherence length,” cond-mat/ 0504431, 2005. 249. A. Laisaar, A. Suisalu, An. Kuznetsov, J. Kikas, “High-pressure lowtemperature spectroscopy of pyrene molecules in commensurate and incommensurate phases of biphenyl,” In: Proc. Joint 20th AIRAPT43rd EHPRG Intern. Conf. on High Pressure Science and Technology, Eds. E.Dinjus, N.Dahmen, No. T5-P129, pp. 1–10, 2005. 250. R. Lõhmus, I. Hussainova, L. Kommel, H. Siimon, “AFM analysis of nano-copper surface morphology,” In: Mechanical Properties of Nanostructured Materials – Experiments and Modeling, Eds. J. G. Swadener, E. Lilleodden, S. Asif, D. Bahr, and D. Weygand (Mater. Res. Soc. Symp. Proc. 880E, Warrendale, PA, 2005), pp. BB5.3.1, 2005. 251. A. Lushchik, A. Kotlov, Ch. Lushchik, V. Nagirnyi, K. Schwartz, E. Vasil’chenko, “Anion excitations in virgin and swift ion irradiated LiF single crystals,” In: HASYLAB Activity Report 2005, DESY, Hamburg, Germany, Part I, pp. 257–258, 2005. 252. A. Lushchik, Ch. Lushchik, E. Feldbach, I. Kudryavtseva, P. Liblik, A. Maaroos, V. Nagirnyi, F. Savikhin, E. Vasil’chenko, “Photon multiplication in wide-gap BAM and SAM aluminates,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 61–72, 2005. 253. V. N. Makhov, J. C. Krupa, M. Kirm, G. Stryganyuk, S. Vielhauer, G. Zimmerer, “VUV luminescence of Lu3+ ions in fluoride matrices,” In: HASYLAB Activity Report 2005, DESY, Hamburg, Germany, Part I, pp. 709–710, 2005. 254. N. Mironova-Ulmane, V. Skvortsova, A. Kuzmin, I. Sildos, “Influence of radiation defects on exciton-magnon interactions in nickel oxide,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 93–97, 2005. 255. A. Niilisk, J. Aarik, T. Uustare, H. Mändar, S. Tkachev, M. H. Manghnani, “A structural study of ZrO2 and HfO2 thin films grown by atomic layer deposition,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 98–105, 2005. Publications • 153 256. I. Ots, H. Liivat, “Asümptootiline vabadus kvantkromodünaamikas,” In: Eesti Füüsika Seltsi aastaraamat 2004, Eesti Füüsika Selts, XV, pp. 46–57, 2005. 257. I. Rebane, “Spontaneous emission rates of a single-impurity molecule in dependence on its orientation in biaxial host crystal,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 202–209, 2005. 258. K. Rebane, “Requirements to impurity activated solids as materials for optical data storage and processing,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 210–214, 2005. 259. V. Reedo, S. Lange, V. Kiisk, T. Tätte, A. Lukner, I. Sildos, “Influence of ambient gas on the photoluminescence of sol-gel derived TiO2:Sm3+ films,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 106–111, 2005. 260. I. Renge, “Lennard-Jones model of disorder in solids,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 215–223, 2005. 261. A. Rosental, “Introduction,” In: Proc. SPIE – Optical Materials and Applications, 5946, pp. xiii, 2005. 262. K. Saal, M. Plaado, I. Kink, A. Kurg, V. Kiisk, J. Koževnikova, U. Mäeorg, A. Rinken, I. Sildos, T. Tätte, A. Lõhmus, “Aminopropyl embedded silica films as potent substrates in DNA microarray applications,” In: Biological and Bio-Inspired Materials and Devices (Mater. Res. Soc. Symp. Proc. 873E, Warrendale, PA, 2005), pp. K93, 2005 (CDR-10, ISBN:1-55899-821-7). 263. V. Sammelselg, J. Aarik, A. Kikas, R. Rammula, T. Käämbre, K. Kooser, A. Zakharov, M. Lulla, I. Martinson, “Study of growth process of ultrathin alumina films deposited on silicon substrates,” In: MAX-LAB Activity Report 2004, National Laboratory, Lund, Sweden, pp. 78–79, 2005. 264. M. Selg, “Reference potential approach to the quantum-mechanical inverse problem: I. Calculation of phase shift and Jost function,” arXiv:quant-ph/0506064, pp. 1–21, 2005. 265. M. Selg, “Reference potential approach to the quantum-mechanical inverse problem: II. Solution of Krein equation,” arXiv:quantph/0506130, pp. 1–22, 2005. 266. M. Selg, “Reference potential approach to the inverse Schrödinger problem: explicit demonstration of Levinson theorem and a solution 154 • Biannual Report 2004/2005 scheme for Krein equation,” arXiv:quant-ph/0512118, pp. 1–26, 2005. 267. M. Selg, “Reference potential approach to the inverse problem in quantum mechanics,” In: The Nineteenth Colloquium on High Resolution Molecular Spectroscopy, Editors: D. Bermejo, J. L. Domenech, M. A. Moreno, ISBN 84-609-6737-9, Universidad de Salamanca, pp. 190–191, 2005. 268. A. Tarre, A. Rosental, T. Uustare, A. Kasikov, “SnO2 on sapphire”, In: Proc. SPIE – Optical Materials and Applications, 5946, pp. 128– 134, 2005. 269. T. Tätte, V. Jacobsen, M. Paalo, R. Branscheid, M. Kreiter, U. Maeorg, K. Saal, A. Lõhmus, I. Kink, “Preparation of Sb doped SnO2 SPM tips and their use as transparent probes in STM induced light hybrid microscopy,” In: NSTI Nanotech 2005, NSTI Nanotechnology Conf. and Trade Show, Anaheim, CA, United States, 3, pp. 305–308, 2005. POPULAR SCIENTIFIC ARTICLES, PUBLICISM 2005 270. A. Freiberg, “Kõige tähtsam energeetika,” Horisont , No. 5, pp. 12– 19, 2005. 271. A. Kasikov, “Türgi – riik või ajalugu?” Eesti Päevaleht, No. 3. jaanuar, pp. , 2005. 272. A. Kikas, “Sünkrotronkiirgus aatomit puurimas,” Horisont, Tallinn, 4, pp. 22–26, 2005. 273. V. Kisand, “Tehnika elushoidmise asemel eksperiment,” Horisont, Tallinn, 3, pp. 28–29, 2005. 274. R. Koch, “Okupatsioonist meis ja meie ümber,” Ajaleht “Rahvuslik Koguja”, Tartu, Eesti, No. 2(35), p. 1, 2005. 275. P. Kuusk, I. Martinson, “Eesti Füüsikud võõrsil IV,” In: Eesti Füüsika Seltsi aastaraamat 2004, Eesti Füüsika Selts, XV, pp. 35–45, 2005. 276. P. Kuusk, “Eessõna,” In: Eesti Füüsika Seltsi aastaraamat 2004, Eesti Füüsika Selts, XV, pp. 3, 2005. 277. P. Kuusk, “Albert Einsteini artikkel “Liikuvate kehade elektrodünaamikas (koos selle artikli I osa tõlkega),” Akadeemia, No. 7, pp. (1392)-1408-1425, 2005. Publications • 155 278. P. Kuusk, “Madis Kõiv,” Estonian Culture, Estonian Institute, IV, No. II, pp. http://www.einst.ee/culture/II_MMIV/kuusk.html, 2005. 279. T. Kärner, “Globaalsetest kriisidest,” Akadeemia, No. 9, pp. 1874– 1890, 2005. 280. T. Kärner, “Eesti välispoliitika dilemmast,” Sirp, No. 33, p. 3, 2005. 281. H. Käämbre, “Koherents ja laserkamm tõid Nobeli preemia,” Horisont, Tallinn, 6, pp. 26–27, 2005. 282. T. Käämbre, “Nüüd oma uurimisrühm Tartus,” Horisont, Tallinn, 6, pp. 30–31, 2005. 283. E. Nõmmiste, “Loodusteaduslik mõtteviis on hädavajalik,” Horisont, Tallinn, 1, pp. 17, 2005. 284. E. Nõmmiste, “Eredam kui tuhat päikest,” Horisont, Tallinn, 3, pp. 20–27, 2005. 285. E. Realo (eelnõu kaasautor), “Keskkonnaministri 26. mai 2005. a määrus nr 45. Kiirgustöötaja ja elaniku efektiivdooside seire ja hindamise kord ning radionukliidide sissevõtust põhjustatud dooside doosikoefitsientide ning kiirgus- ja koefaktori väärtused,” RTL, 16.06.2005, Tallinn, Eesti, 65, No. 934, 2005. 286. E. Realo (eelnõu kaasautor), “Keskkonnaministri 15. veebruari 2005. a määrus nr 10. Kiirgustegevuses tekkinud radioaktiivsete ainete või radioaktiivsete ainetega saastunud esemete vabastamistasemed ning nende vabastamise, ringlusse võtmise ja taaskasutamise tingimused,” RTL, 01.03.2005, Tallinn, Eesti, 24, No. 331, 2005. 287. E. Realo (eelnõu kaasautor), “Keskkonnaministri 9. veebruari 2005. a määrus nr 8. Radioaktiivsete jäätmete klassifikatsioon, registreerimise, käitlemise ja üleandmise nõuded ning radioaktiivsete jäätmete vastavusnäitajad,” RTL, 17.02.2005, Tallinn, Eesti, 20, No. 244, 2005. 288. K. Rebane, “Terrorism – tsivilisatsiooni tulevik?” Akadeemia, No. 6, pp. 1175–1187, 2005. 289. K. Rebane, “Veel mõni sõna terrorismiohust,” Akadeemia, No. 12, pp. 2742, 2005. 290. K. Rebane, “Erasektor tervishoiule appi,” Äripäev, 10.01.2005. 291. K. Rebane, “Ahistav vanusepiir,” Postimees, 11.05.2005. 292. K. Rebane, “Õiglustunne avaramaks,” Postimees, 09.11.2005. 293. A. Rosental, “Nanotehnoloogia,” In: Eesti Teadusfondi Aastaraamat 2004, Eesti Teadusfond, pp. 14, 2005. 156 • Biannual Report 2004/2005 294. Ɏ. ɋɚɜɢɯɢɧ, Ⱥ. Ʉɚɫɢɤɨɜ, “ɍɧɢɤɚɥɶɧɨɫɬɶ ɫɬɚɪɨɨɛɪɹɞɱɟɫɬɜɚ ɗɫɬɨɧɢɢ ɢ ɫɨɫɬɚɜɚ ɫɥɨɜ ɹɡɵɤɚ ɫɬɚɪɲɟɝɨ ɩɨɤɨɥɟɧɢɹ ɪɭɫɫɤɢɯ Ɂɚɩɚɞɧɨɝɨ ɉɪɢɱɭɞɶɹ ɫɟɪɟɞɢɧɵ 20 ɜɟɤɚ,” In: Ⱦɟɧɶ ɤɭɥɶɬɭɪɵ ɉɪɢɱɭɞɶɹ, Ɍɚɥɥɢɧɧ 2005, p. 8.15, 2005. 295. Ɏ. ɋɚɜɢɯɢɧ, Ⱥ. Ʉɚɫɢɤɨɜ, “Ɋɭɫɫɤɢɟ ɜ ɉɪɢɱɭɞɶɟ: Ʉɬɨ ɨɧɢ?” Ɇɨɥɨɞɺɠɶ ɗɫɬɨɧɢɢ, 27 ɦɚɹ, 3 ɢɸɧɹ, 17 ɢɸɧɹ, 2005. 296. Ɏ. ɋɚɜɢɯɢɧ, Ⱥ. Ʉɚɫɢɤɨɜ, “Ɉ ɩɪɚɜɨɫɥɚɜɧɵɯ ɜ ɩɨɥɶɫɤɨ–ɲɜɟɞɫɤɢɣ ɩɟɪɢɨɞ,” Peipsirannik, No. 4, 2005. BOOKS, BOOKLETS 2005 297. M. Kiisk, E. Realo (tõlkijad), “Tuumasünteesiuuringud: võimalik tulevikuenergia Euroopa jaoks (Tõlge eesti keelde),” Euroopa Ühenduste Ametlike Väljaannete Talitus, ISBN 92-894-7723-7, Euroopa Komisjon, Luksemburg, 40 pp., 2005 . 298. M. Kiisk, E. Realo (tõlkijad), “ITER. Termotuumaenergia maailmale (Tõlge eesti keelde),” Seeria: Euroopa uurimistegevus huviorbiidis, Euroopa Komisjon, Informatsiooni- ja kommunikatsiooniosakond, Brüssel, 8 pp., 2005. 299. A. Rosental (editor), “Optical Materials and Applications,” Proc. SPIE – Optical Materials and Applications, 5946, pp. xiii,1–530, 2005. 6. TALKS AND POSTERS AT CONFERENCES ORAL PRESENTATIONS 2004 1. 2. 3. 4. 5. 6. 7. 8. J. Aarik. In situ QCM studies of atomic layer deposition of high-k oxides. ALD2004, Helsinki, Finland, Aug. 16–18, 2004 (invited paper). M. Agåker, J. Söderström, T. Käämbre, C. Glover, L. Gridneva, T. Schmitt, A. Augustsson, M. Mattesini, R. Ahuja, and J. E. Rubensson. Resonant inelastic soft X-ray scattering at hollow lithium states in solids. The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, July 19–23, 2004. V. Fedoseyev. Reflection and refraction of a light beam carrying the angular orbital momentum. 3rd Intern. Conf. „Basic Problems of Optics”, St. Petersburg, Russia, October 18–21, 2004. A. Freiberg. Õppetooli ülevaade. TÜMRI ja Eesti Biokeskuse aastakonverents 2003, Tartu, 13.–14. dets., 2004. A. Freiberg. Pettus teaduses. Tartu Rotary lõuna, Tartu, 19. märts 2004. A. Freiberg, M. Rätsep, K. Timpmann. Low-lying excitonic polaron states in core LH1 and peripheral LH2 bacterial light-harvesting complexes: A hole burning and fluorescence line narrowing study. Conf. of ESF Femtochemistry & Femtobiology (ULTRA) Program, Pecs, Hungary, March 25–28, 2004 (invited paper). A. Freiberg. Excitonic polarons in photosynthesis. PS 2004 LightHarvesting Systems Workshop, Sainte-Adele, Canada, Aug. 26–29, 2004 (invited paper). V. Hizhnyakov, V. Boltrushko. Anomalous optical spectra of centers with soft phonon dynamics in the excited state. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004 (invited paper). 158 • Biannual Report 2004/2005 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. V. Hizhnyakov, G. Benedek. Quantum diffusion: effects of local distortion of phonons. 11th Intern. Conf. on Phonon Scattering in Condensed Matter (Phonons 2004), St. Petersburg, Russia, July 25– 30, 2004. V. Hizhnyakov, V. Boltrushko, H. Kaasik, A. Shelkan. Multiphonon processes in impurity centres: nonperturbative theory. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004 (invited paper). R. Jaaniso, T. Avarmaa, A. Suisalu, A. Floren, A. Ruudi, K. Õige. Stability of luminescence decay parameters in oxygen-sensitive polymer films doped with Pd-porphyrins. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. M. Kiisk. Improvement of the AMS-technique at the Lund AMS facility”. Seminar Central 14C Analysis Facility, Max-Planck-Institute for Biogeochemistry , Jena, Saksamaa, February 9, 2004. M. Kiisk. Experience and improvement of the AMS-technique at the Lund AMS facility. Seminar Ion Beam Physics, ETH Institute for Particle Physics, Zürich, Šveits, March 15, 2004. J. Kikas, A. Suisalu, An. Kuznetsov, A. Laisaar, V. Hizhnyakov. Pressure Effect on Relaxation in Glasses: A Persistant Spectral Hole Burning Study. High Resolution Site Selective Spectroscopy, An Intern. Conf. in Memory of Roman I. Personov, Bayreuth, Germany, July 15– 18, 2004 (invited paper). A. Kikas. Creation and Decay of X-Ray Excitations in ionic solids. Synchrotron Radiation Summer School, Kääriku, Estonia, June 2–4, 2004. A. Kikas. Röntgenkiirguse Ramani hajumine. XXXIV Eesti Füüsikapäevad, Tartu Estonia, 13.–14.veebr. 2004. A. Kikas. Sünkrotronkiirgus: Mis, Kuidas, Milleks?. Noorfüüsikute sügiskool, Kääriku, Estonia, Oct. 8–10, 2004. M. Kirm, A. Lushchik, Ch. Lushchik. Creation of groups of spatially correlated excitations in wide-gap solids. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004 (invited paper). V. Kisand, E. Nõmmiste, E. Kukk, M. Huttula, A. Koivukangas, A. Calo, H. Aksela, S. Aksela. Photoexcitation, –ionization and fragmentation of molecular CsCl and rubidium halides. Meeting of the NORFA Talks and Posters at Conferences • 159 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. financed network “Synchrotron-based electron spectroscopy”, Tartu, Estonia, March 15, 2004. M. Kleemann, A. Suisalu, J. Kikas. Polymer film doped with solvatochromic dye for humidity measurement. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. R. Koch. Tartu rahu 84. aastapäeval. Tartu rahulepingu sõlmimise 84. aastapäevale pühendatud kõnekoosolek, Tartu, Eesti, 2. veebr. 2004 (invited paper). K. Kooser, R. Ruus, A. Saar, E. Nõmmiste, A. Kikas. Cs 3d absorption and resonant photoemission study of caesium halogenides. Meeting of the NORFA financed network “Synchrotron-based electron spectroscopy”, Tartu, Estonia, March 15, 2004. A. Krasnikov, M. Nikl, S. Zazubovich. Origin of green emission in PbWO4 crystals. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Lavia, July 11–16, 2004. N. Kristoffel, P. Rubin. Cuprate energetic characteristics in a multiband scenario with doping driven spectral overlaps. 4th Intern. Conf. Nanoscale Heterogeneity and Quantum Phenomena in Complex Matter (Stripes and Superconductivity, Stripes04), Rome, Italy, Sept.26– Oct.2, 2004 (invited paper). N. Kristoffel, P. Rubin. Kupraatülijuhtide energeetilised karakteristikud ja nende seosed dopeeringskaalal. XXXIV Eesti Füüsikapäevad, Tartu, Estonia, 13.–14.veebr. 2004. E. Kukk, M. Huttula, J. Rius i Riu, H. Aksela, S. Aksela, R. Ruus. VUV-induced processes in alkali halide dimer molecules – how well does the ionic approach work? The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, July 19–23, 2004. K. Kukli, M. Ritala, T. Pilvi, T. Aaltonen, J. Aarik, M. Leskelä. Factors influencing atomic layer deposition rate and phase composition of high permittivity oxide layers. E-MRS2004, Strasbourgh, France, May 24– 28, 2004. P. Kuusk. Mida teha populaarteadusliku kirjandusega. VI semiootika sügiskool, Kääriku, 6.–7.nov., 2004. H. Käämbre. Eesti teaduskeelest ja argikeelest. Kuku raadio saates Keelekuku, Tartu, Estonia, Nov. 8, 2004. 160 • Biannual Report 2004/2005 30. H. Käämbre. Mikrokeeriste maailmas (2003.a. Nobeli füüsikapreemiast). XXXIV Eesti Füüsikapäevad, Tartu, Estonia, Febr. 13, 2004. 31. H. Käämbre. Mikrokeeriste maailmas (2003.a. Nobeli füüsikapreemiast). Eesti füüsikaõpetajate päev, Tallinn, Estonia, March 24, 2004. 32. H. Käämbre. Mikrokeeriste maailmas (2003.a. Nobeli füüsikapreemiast). Tallinna Reaalkoolis, Tallinn, Estonia, April 14, 2004. 33. H. Käämbre. Emakeel argi- ja teaduskeelena. F.J. Wiedemanni keelepäev, Väike-Maarja, Estonia, April 21, 2004. 34. H. Käämbre. Emakeel argi- ja teaduskeelena. Eesti Kirjanduse Seltsi koosolek, Tallinn, Estonia, May 15, 2004. 35. H. Käämbre. Laser-mis? kuidas? milleks? Loeng TÜ biogeoteaduskonna üliõpilastele (prof. A. Freibergi loengukursuse raames), Tartu, Estonia, Nov. 3, 2004. 36. H. Liivat, I. Ots. Nobeli preemia füüsikas 2004. EFS noorte füüsikute VI sügiskool, Kääriku, 8.–10.okt. 2004. 37. A. Lushchik, Ch. Lushchik, P. Liblik, A. Maaroos, V. Nagirnyi, F. Savikhin. Photon multiplication in wide-gap BAM and SAM aluminates. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004 (invited paper). 38. M. Lust, H. Putnik, E. Realo. Preliminary Long-Term Radiological Safety Assessment for the Paldiski Radioactive Waste Interim Storage Facility, Estonia. Baltic-Swedish Seminar Transfer of knowledge and experience in safety and risk assessment methods for radwaste facilities, Studsvik, Sweden , 23–27 February, 2004 (invited paper). 39. A. Lõhmus. Force interactions in nanowire-based nanoelectromechanical devices. 3rd ESF Nanotribology Workshop, Sesimbra, Portugal, Sept. 18–24, 2004. 40. E. Nõmmiste, V. Kisand, M. Valden, M. Hirsimäki, E. Kukk, T. Käämbre, R. Ruus, A. Kikas. Studing KF monolayers on copper substrate. Fifth Nordic Conf. on Surface Science, Tampere, Finland, Sept. 22–25, 2004. 41. E. Realo. Kiirgusohutus täna ja homme. Eesti Radioloogia Ühingu õppepäev, Põlva, Eesti, 5. juuni 2004 (invited paper). 42. I. Rebane. Spontaneous emission rates of a single impurity molecule in dependence on its orientation in biaxial host crystal. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. Talks and Posters at Conferences • 161 43. K. Rebane. Aatomituumade madala energiaga isomeerseisundid. Uus laine? XXXIV Eesti Füüsikapäevad, Tartu, Estonia, Febr. 13–14, 2004. 44. K. Reivelt. World Year of Physics in Estonia. Preparatory meeting of European Physical Society on WYP2005, Mulhouse, France, Oct. 4, 2004. 45. I. Renge. Lennard-Jones model of disorder in solids. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. 46. I. Renge. Lennard-Jones approach to inhomogeneous broadening in glasses. High Resolution Site Selective spectroscopy, Intern. Conf. in Memory of Roman Personov, Bayreuth, Germany, July 15–18, 2004. 47. M. Saal. Viies element. Eesti XXVI füüsikaõpetajate päevad, Tartu, 24.märts, 2004. 48. P. Saari. Localized waves and relativity. Progress in electromagnetic research symposium, PIERS’04, Pisa, Italy, March 28–31, 2004 (invited paper). 49. P. Saari. Infotehnoloogia tulevik – kas à la Marx või Malthus, Fukuyama või Huntington? ITT foorumi, Pärnu, Sept. 16–17, 2004 (invited paper). 50. P. Saari. Localized waves in ultrafast optics. Seminar of the Max-BornInstitut für Nichlineare Optik und Kurzzeitsspektroskopie, Berlin, Germany, July 7, 2004 (invited paper). 51. P. Saari. Kuivõrd lokaliseeritav on footon ruumis? Spektroskoopiaseminar, TÜFI, Tartu, Sept. 9, 2004. 52. P. Saari. Teadmistepõhine või ignorantsusepõhine Eesti? Ettekanne Tartu Rotary klubis, Tartu, Nov. 24, 2004. 53. A. Sherman. Spectral and magnetic properties of the t-J model of cuprate perovskites. Workshop “Modelling and Simulation in Molecular Systems, Mesoscopic Structures, and Material Science”, Chemnitz, Germany, April 21–23, 2004 (invited paper). 54. A. Sherman, M. Schreiber. Resonance peak and incommensurability in cuprate perovskites. 2nd Euro-Asian Symposium “Trends in Magnetism” (EASTMAG-2004), Krasnoyarsk, Russia, August 24–27, 2004. 55. A. Sherman. Magnetic properties of cuprate perovskites. NATO Advance Research Workshop “Smart Materials for Ranging Systems”, Krasnoyarsk, Russia, Aug. 29–Sept. 1, 2004 (invited paper). 162 • Biannual Report 2004/2005 56. I. Sildos, V. Kiisk, S. Lange, J. Aarik, M. Kirm. Photoluminescence of RE-doped thin metal oxide films. XIIth Feofilov Symp., Ekaterinburg, Russia, Sept. 22–25, 2004. 57. S. Zazubovich, Y. Usuki, I. Sildos, M. Nikl, A. Krasnikov, V. Kiisk, N. Senguttuvan, P. Bohacek. Red emission of PbWO4 crystals. XXXIV Eesti Füüsikapäevad, Tartu, Estonia, Febr. 13–14, 2004 (invited paper). POSTER PRESENTATIONS 2004 58. J. Aarik, T. Tätte, V. Kiisk, S. Lange, I. Sildos. Põhiainelt lisanditsentrile toimuva energiaülekande spektroskoopilised uuringud haruldaste muldmetallidega dopeeritud metalloksiidkiledes ja fiibrites. XXXIV Eesti Füüsikapäevad, Tartu, Eesti, 13.–14.veebr. 2004. 59. J. Aarik, V. Bitševin, I. Jõgi, H. Käämbre, M. Laan, V. Sammelselg. Tunnelvoolud kilepakettides. XXXIV Eesti Füüsikapäevad, Tartu, Eesti, 13.–14.veebr. 2004. 60. J. Aarik, A. Kasikov, M. Kirm, S. Lange, T. Uustare, H. Mändar. Optical properties of crystalline Al2O3 thin films grown by atomic layer deposition. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. 61. J. Aarik, I. Jõgi, K. Kukli, H. Käämbre, M. Laan. Conduction mechanisms in metal-dielectric-metal structures. ALD2004, Helsinki, Finland, Aug. 16–18, 2004. 62. R. Aceves, P. Perez Salas, T. M. Piters, S. Zazubovich. Self-trapped exciton luminescence and reabsorption in KI:Eu2+ crystals. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. 63. P. Adamson. Characteristic reflection angles of nanoscopic layered media and optical probing of ultrathin dielectric films. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. 64. A. Agui, S. Butorin, T. Käämbre, C. Såthe, T. Saitoh, Y Moritomo, J Nordgren. Resonant O Ka Emission Spectroscopy of double layered Manganite La1.2Sr1.8Mn2O7. The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, July 19–23, 2004. Talks and Posters at Conferences • 163 65. T. Avarmaa, T. Jantson, H. Mändar, T. Uustare, R. Jaaniso. Nanocrystalline Cr2O3-TiO2 thin films by pulsed laser deposition. E-MRS 2004 Fall Meeting, Warsaw, Poland, Sept. 6–10, 2004. 66. V. Babin, K. Blazek, A. Krasnikov, K. Nejezchleb, M. Nikl, T. Savikhina, S. Zazubovich. Luminescence of undoped LuAG and YAG crystals. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. 67. G. Benedek, V. Hizhnyakov. The Role of Defect-Induced Phonon Localization in Quantum Diffusion. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM–2004), Riga, Latvia, July 11–16, 2004. 68. P. Bohacek, P. Fabeni, A. Krasnikov, M. Nikl, G. P. Pazzi, C. Susini, S. Zazubovich. Defects creation under UV-irradiation of PbWO4 crystals. 14th Intern. Conf. on Solid State Dosimetry (SSD14), Yale Univ., New Haven, USA, June 27-July 2, 2004. 69. P. Bohacek, P. Fabeni, A. Krasnikov, M. Nikl, G. P. Pazzi, C. Susini, S. Zazubovich. Defects in UV-irradiated PbWO4:Mo crystals monitored by TSL measurements. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. 70. S. Dolgov, A. Kärkkänen, T. Kärner, A. Maaroos. Low-temperature (4295 K) thermoluminescence of pure and doped MgO and CaO single crystals. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. 71. C. Glover, M. Agåker, T. Käämbre, T. Schmitt, M. Adell, L. Ilver, J. Kanski, L. Kjeldgaard, and J. E. Rubensson. Localized 3d excitations in Ge, GaAs, and GaN, populated in inelastic soft X-ray scattering, resonantly enhanced at the 3p edges. The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, July 19–23, 2004. 72. C. Glover, T. Käämbre, M. Agaker, L. Gridneva, T. Balasubramanian, J. Andersen, J. E. Rubensson. Effects of momentum conservation in resonant inelastic soft X-ray scattering in the bulk and at the surface of Be metal. The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, July 19–23, 2004. 73. V. Hizhnyakov, J. Kikas, J. Takahashi, A. Laisaar, A. Suisalu, An. Kuznetsov. Low-energy excitations in glasses under high pressure: isothermal and cycling effects. 11th Intern. Conf. on Phonon Scattering in Condensed Matter (Phonons 2004), St.Petersburg, Russia, July 25– 30, 2004. 164 • Biannual Report 2004/2005 74. V. Hizhnyakov, J. Kikas, J. Takahashi, A. Laisaar, A. Suisalu, An. Kuznetsov. Two-level systems in glasses under high pressure: temperature cycling effect. 11th Intern. Conf. on Phonon Scattering in Condensed Matter (Phonons 2004), St. Petersburg, Russia, July 25– 30, 2004. 75. V. Issahanyan, T. Kärner, A. Maaroos, S. Nakonechnyi. Spin relaxation processes in the defect hole centres of Be doped MgO single crystals. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. 76. E. Jalviste, N. Ohta. Electric field induced reorientation of polar molecules in a poly(methyl methacrylate) film studied by electroabsorption spectroscopy. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. 77. V. Kiisk, I. Sildos, S. Lange, V. Reedo, T. Tätte, M. Kirm, J. Aarik. Photoluminescence characterization of pure and Sm3+–doped thin metal oxide films. E-MRS 2004, Strasbourg, France, May 24–28, 2004. 78. A. Kikas, T. Käämbre, A. Saar, K. Kooser, E. Nõmmiste, I. Martinson. Resonant Inelastic X-ray Scattering at the K edge of oxygen and fuorine in insulators. The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, July 19–23, 2004. 79. A. Kikas, J. Aarik, T. Käämbre, V. Kisand, A. Zakharov, V. Sammelselg, I. Martinson. An X-ray photoabsorption and photoelectron spectroscopy study of ZrO2 and HfO2 films prepared by atomic layer deposition. Meeting of the NORFA financed network “Synchrotronbased electron spectroscopy”, Tartu, Estonia, March 15, 2004. 80. P. Konsin, B. Sorkin. A Gigantic Photoinduced dielectric constant of quantum paraelectric perovskite oxides under a weak electric field in the electron-lattice theory. 7th European Conf. on Application of Polar Dielectrics (ECAPD7), Liberec, Czech Republic, September 6–9, 2004. 81. P. Konsin, B. Sorkin. Generalized multiple gap model for the superconductivity in MgB2. 4th Intern. Conf. Nanoscale Heterogeneity and Quantum Phenomena in Complex Matter (Stripes and Superconductivity, Stripes04), Rome, Italy, September 26 – October 2, 2004. 82. M. Korshunov, S. Ovchinnikov, A. Sherman. Effective Hamiltonian and the properties of normal and superconducting phases of n-type cuprates. Talks and Posters at Conferences • 165 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. Intern. Conf. on Strongly Correlated Electron Systems, Karlsruhe, Germany, July 26–30, 2004. A. Kotlov, S. Dolgov, E. Feldbach, L. Jönsson, M. Kirm, A. Lushchik, V. Nagirnyi, G. Svensson, B. Zadneprovki. Exciton and recombination luminescence of Al2(WO4)3 crystals. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. A. Krasnikov, M. Nikl, A. Stolovits, Y. Usuki, S. Zazubovich. Luminescence of the PbWO4:5% Cd crystal. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. P. Kuusk, M. Saal. A cosmological model for a two-brane world. 17th Intern. Conf. on General Relatively and Gravitation, Dublin, Ireland, July 18–23, 2004. T. Kärner, A. Maaroos, S. Nakonechnyi. EPR spectra of the defect centres created by neutron irradiation in MgO. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11– 16, 2004. A. Lõhmus. Cryogenic Cleaning of SPM Tips. Nordic-Baltic SPM 2004 workshop, Trondheim, Norway, June 16–19, 2004. R. Lõhmus. AFM characterization of surface morphology of severe plastic deformed copper. 3rd ESF Nanotribology Workshop, Sesimbra, Portugal, Sept. 18–24, 2004. R. Lõhmus. AFM characterization of the surface morphology of the severe plastic deformed copper. Nordic-Baltic SPM 2004 Workshop, Trondheim, Norway, June 16–19, 2004. R. Lõhmus. In situ transformations of gold contacts studied by molecular dynamics simulations. Intern. Conf. on Nanotechnology (NANOTECH 2004), Boston, USA, March 7–11, 2004. D. Di Martino, A. Krasnikov, M. Nikl, K. Nitsch, A. Vedda, S. Zazubovich. The 3.83 eV luminescence of Gd/enriched phosphate glasses. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. K. Mauring, V. Krasnenko, A. Tkaczyk, E. Tkaczyk, Ö. Farkas. Molecular vibrations of green fluorescent protein. 5th Intern. Conf. on Biological Physics (ICBP 2004), Göteborg, Sweden, Aug. 23–27, 2004. 166 • Biannual Report 2004/2005 93. K. Mauring, V. Krasnenko, A. Tkaczyk, E. Tkaczyk, Ö. Farkas. Properties of green fluorescent protein determined by molecular vibrations. SIMU-2004 – Bridging the Scales, Genua, Italy, Aug. 29–31, 2004. 94. A. Niilisk, J. Aarik, T. Uustare, H. Mändar, S. Tkachev, M. H. Manghnani. Structural study of ZrO2 and HfO2 thin films grown by atomic layer deposition. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. 95. E. Nõmmiste, V. Kisand, E. Kukk, A. Calo, H. Aksela, S. Aksela. Photoexcitation, -ionization and fragmentation of molecular rubidium halides. The 14th Intern. Conf. on Vacuum Ultraviolet Radiation Physics, Cairns, Australia, July 19–23, 2004. 96. E. Nõmmiste, V. Kisand, M. Hirsimäki, M. Valden, E. Kukk, T. Käämbre, R. Ruus, A. Kikas. Studying insulator monolayers on metal substrate. Meeting of the NORFA financed network “Synchrotronbased electron spectroscopy”, Tartu, Estonia, March 15, 2004. 97. V. Peet, S. Shchemeljov. Coherent wave-mixing processes and multiphoton ionization in spatially incoherent conical laser beams. 28th European Conf. on Laser Interaction with Matter, Rome, Italy, Sept. 6–10, 2004. 98. V. Peet, S. Shchemeljov. Four-wave mixing in spatially incoherent laser beams. XXXIV Eesti Füüsikapäevad, Tartu, Eesti, Feb. 13–14, 2004. 99. R. Rammula, J. Aarik, A. Kikas, T. Käämbre, V. Sammelselg. AFM and XPS studies of ultrathin HfO2 films prepared by ALD. 5th NordicBaltic Scanning Probe Microscopy Workshop, Trondheim, Norway, June 16–19, 2004. 100. R. Rammula, J. Aarik, A. Kikas, T. Käämbre, V. Sammelselg. Nucleation of HfO2 films deposited by chloride and iodide ALD process. ALD2004, Helsinki, Finland, August 16–18, 2004. 101. K. Realo, R. Koch, M. Lust, A. Uljas, E. Realo. Lead-210 in air and surface soil in NE Estonia. 11th Intern. Congress of Intern. Radiation Protection Association (IRPA), Madrid, Spain, 23–28 May, 2004. 102. K. Rebane. Requirements to impurity activated solis as materials for optical data storage and processing . 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. 103. V. Reedo, S. Lange, V. Kiisk, T. Tätte, I. Sildos. Influence of ambient gas to the photoluminescence of rare-earth ions in sol-gel derived metal Talks and Posters at Conferences • 167 104. 105. 106. 107. 108. 109. 110. 111. 112. 113. oxide films. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. P. Rubin, A. Sherman. Magnetic properties of the 2D Heisenberg model on a triangular lattice. 30th Intern. Winter School-Symposium of theorists “Kourovka-2004”, Kyshtym, Russia, Feb. 22–28, 2004. R. Ruus, K. Kooser, E. Nõmmiste, A. Saar, I. Martinson, A. Kikas. Potential barrier effects in Cs 3d resonance photoemission of CsF. Meeting of the NORFA financed network “Synchrotron-based electron spectroscopy”, Tartu, Estonia, March 15, 2004. R. Ruus. A crystal-field calculation program for ionic solids and molecules. Synchrotron Radiation Summer School, Kääriku, Estonia, June 2–4, 2004. K. Saal, M. Plaado, T. Tätte. Aminofunktsionaalsete sool-geelkilede valmistamine ja rakendused biotehnoloogias. XXXIV Eesti Füüsikapäevad, Tartu, Estonia, 13.–14.veebr. 2004. V. Sammelselg, J. Aarik, A. Kikas, R. Rammula, T. Käämbre, K. Kooser, J. Lu, K. Kukli. XPS investigation of ultrathin ALD films and interface layers. ALD2004, Helsinki, Finland, August 16–18, 2004. F. Savikhin, M. Kerikmäe, E. Feldbach, A. Lushchik, D. Onishchik, D. Rakhimov, I.Tokbergenov. Fast intrinsic emission with the participation of oxyanion and cation excitations in metal sulphates. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. M. Selg, P. Miidla. Solution of quantum-mechanical inverse problem based on complete knowledge of the phase shift. 8th European Conf. on Atomic and Molecular Physics (ECAMP VIII), Rennes, France, July 6–10, 2004. A. Sherman, M. Schreiber. Resonance peak and incommensurability in cuprate perovskites. 20th General Conf. of Condensed Matter Division of European Phys. Society, Prague, Czech Republic, July 19–23, 2004. I. Sildos, V. Kiisk, S. Lange, J. Aarik, M. Kirm. Photoluminescence of RE-doped thin metal oxide films. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. A. Stolovits, R. K. Kremer, H. Mattausch, A. Sherman, A. Simon. Quantum interference of electrons in Nb5Te4. 20th General Conf. of Condensed Matter Division of European Phys. Society, Prague, Czech Republic, July 19–23, 2004. 168 • Biannual Report 2004/2005 114. A. Tarre, A. Rosental, T. Uustare, A. Kasikov. SnO2 on sapphire: amorphous, polycrystalline and epitaxial films. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. 115. A. Tarre, J. Harjuoja, A. Aidla, T. Uustare, J. Aarik, A. Rosental, L. Niinistö. Comparison of atomic layer deposition of SnO2 from SnI4 and O2 on different substrates. ALD2004, Helsinki, Finland, August 16–18, 2004. 116. I. Tehver. Calculation of CARS excitation spectrum by transform method. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. 117. I. Tehver. Calculation of CARS excitation profile of ZnPc: manifestation of Herzberg-Teller interaction. 11th Intern. Conf. on Phonon Scattering in Condensed Matter (Phonons 2004), St. Petersburg, Russia, July 25– 30, 2004. 118. K. Timpmann, M. Rätsep, A. Freiberg. Emitting excitonic polaron states in core LH1 and peripheral LH2 bacterial light-harvesting complexes. 14th Intern. Congress on Photobiology, Jeju, Korea, June 10–15, 2004. 119. G. Trinkunas, A. Freiberg. Abrupt exciton self-trapping in finite and disordered one-dimensional aggregates. EXCON '04 6th Intern. Conf. on Excitonic Processes in Condensed Matter, Krakow, Poland, July 6– 9, 2004. 120. E. Vasil’chenko, I. Kudryavtseva, A. Lushchik, Ch. Lushchik, V. Nagirnyi. Selective creation of colour centres and peaks of thermally stimulated luminescence by VUV photons in LiF single crystals. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. 121. P. Vois, A. Suisalu, An. Kuznetsov, R. Jaaniso, H. Bill. Characterization of Sm2+ centers in Ba12F19Cl5–xBrx crystals by 5D0–7F0 luminescence and spectral hole burning. 4th Intern. Conf. on Advanced Optical Materials and Devices (AOMD-4), Tartu, Estonia, July 6–9, 2004. 122. A. Voloshinovskii, I. Pashuk, G. Struganyuk, S. Zazubovich. Chargetransfer luminescence processes. 15th Intern. Conf. on Defects in Insulating Materials (ICDIM-2004), Riga, Latvia, July 11–16, 2004. Talks and Posters at Conferences • 169 ORAL PRESENTATIONS 2005 123. J. Aarik, A. Rosental, A. Tarre. Atomic layer deposition of nanostructured materials for microelectronic and sensoric applications. National Conf. of Network for Nanostructured Materials of ACC on Nanopowders, Nanostructured Materials and Coatings, Tallinn, Estonia, March 17, 2005. 124. J. Aarik. Aatomkihtsadestamine: alusuuringutest rakendusteni. XXXV Eesti Füüsikapäevad, Tartu, 22.–23. märts, 2005 (invited paper). 125. V. Babin, M. Kink, Y. Maksimov, K. Nejezchleb, M. Nikl, S. Zazubovich. VUV spectroscopy of Sc3+ and Ce3+ doped LuAG crystals. Intern. Conf. “Vacuum Ultraviolet Spectroscopy and Interaction with Condensed Matter” (VUV 2005), Irkutsk, Russia, July 18–22, 2005. 126. V. Babin, M. Kink, Y. Maksimov, K. Nejezchleb, M. Nikl, S. Zazubovich. Luminescence of undoped and Ce3+-doped Lu(Sc,Y)AG crystals. 14th Intern. Conf. on Luminescence (ICL’05), Beijing, China, July 25–29, 2005. 127. A. Freiberg, M. Rätsep, K. Timpmann, G. Trinkunas. Band structure, static disorder, and electron-lattice coupling distinguishing photosynthetic antenna excitons. Intern. Conf. on Luminescence, Peking, China, July 25–29, 2005. 128. A. Freiberg. The antenna polarons. Intern. Conf. on Luminescence, Institute of Physics, Chinese Academy of Sciences, Peking, China, July 27, 2005 (invited paper). 129. A. Freiberg, M. Rätsep, K. Timpmann, G. Trinkunas. Band structure and dynamics of photosynthetic antenna excitons. 15th Intern. Conf. on Dynamical Processes in Excited States of Solids, Shanghai, China, Aug. 1–5, 2005. 130. A. Freiberg. Miks on metsad rohelised? TÜMRI ja Eesti Biokeskuse aastakonverents 2005, Tartu, 14.–15. dets. 2005. 131. G. Gerasimov, R. Hallin, B. Krylov, A. Treshchalov, A. Morozov, A. Lissovski, G. Zwereva, A. Arnesen. The intense VUV narrow band emission from an inert gas mixture discharge. VII Intern. Conf. on Atomic and Molecular Pulsed Lasers, Tomsk, Russia, Sept. 12–16, 2005 (invited paper). 132. I. Jõgi, J. Aarik, K. Kukli, H. Käämbre, M. Laan, J. Lu, T. Sajavaara, T. Uustare. The effect of precursors on the structure and conductivity of 170 • Biannual Report 2004/2005 133. 134. 135. 136. 137. 138. 139. 140. 141. 142. 143. 144. 145. atomic layer deposited TiO2 films. Fifteenth Euoropean Conf. on Chemical Vapor Deposition (EUROCVD-15), Bochum, Germany, Sept. 4–9, 2005. L. Järv. Entroopia, elu ja (füüsikaline) eshatoloogia. Molekulaarbioloogia talvekool, Kääriku, 4.–6. veebr. 2005 (invited paper). L. Järv. Silmapaistvat viimase aasta teoreetilises alusfüüsikas. TÜ Suveülikooli raames toimunud füüsikaõpetajate seminar-konverents “Füüsika õpetamise probleemid”, Tartu, 28. juuni 2005 (invited paper). L. Järv. Kujutlusvõime laboratoorium: mõtteeksperimendid füüsikas. Teaduse ja religiooni kolleegiumi II kevadkool “Loodus, kultuur, kujutlusvõime”, Põltsamaa, 22.–23. aprill 2005 (invited paper). L. Järv. Varp-masinate lahendid üldrelatiivsusteoorias. TÜ teoreetilise füüsika seminar, Tartu, 6. dets. 2005. L. Järv. Stringiteooria kompaktifitseerimine ja kiirenevalt paisuv Universum. TÜ teoreetilise füüsika seminar, Tartu, 29. märts 2005. L. Järv. Stringiteooria alternatiivuniversumite “maastik”. TÜ teoreetilise füüsika seminar, Tartu, 15. märts 2005. L. Järv. Kõrgemat järku kalibratsiooniteooriatest. TÜ teoreetilise füüsika seminar, Tartu, 8. märts 2005. L. Järv. Tume energia ja maailma lõpp. TÜ teoreetilise füüsika seminar, Tartu, 1. märts 2005. L. Järv. Accelerating Universe and Moduli Stabilisation from String Theory Compactifications. HIP String and QFT group weekly Journal Club, Helsinki, Finland, Feb. 14, 2005. L. Järv. Creation and decay of X-ray excitations in ionic solids. NordForsk Network Meeting “Synchrotron-based Electron Spectroscopy”, Aalborg and Rebild Bakker, Denmark, April 25–26, 2005. A. Kasikov. Dependence of the obtained thin film optical parameters on a computing procedure. 13th Intern. Congress on Thin Films ICTF13/ACSIN8, Stockholm, Sweden, June 19–23, 2005. M. Kiisk. Tritium depths profile measurements in inner wall tiles from ASDEX-Upgrade, JET and TFTR. Estonian-Finnish Fusion Collaboration Seminar, Tallinn, Dec. 8, 2005 (invited paper). M. Kirm, J. Aarik, E. Feldbach, S. Lange, H. Mändar, T. Uustare. Luminescence spectroscopy of thin oxide films grown by atomic layer Talks and Posters at Conferences • 171 146. 147. 148. 149. 150. 151. 152. 153. 154. 155. deposition. 207th Meeting of Electrochemical society, Quebec City, Canada, May 13–20, 2005. M. Kirm, V. Babin, V. Nagirnyi, N. Shiran, V. Voronova, V. Nesterkina, K. Shimamura, K. Kitamura, E. Villora. Spectroscopic investigations of fluoride based scintillating materials. Intern. Conf. on Inorganic Scintillators and their Industrial Applications (SCINT2005), Alushta, Ukraine, Sept. 19–23, 2005. A. Krasnikov, M. Nikl, S. Zazubovich. Processes resulting in thermal quenching of the blue emission in PbWO4 crystals. Intern. Conf. on Inorganic Scintillators and their Industrial Applications (SCINT2005), Alushta, Ukraine, Sept. 19–23, 2005. N. Kristoffel. Free energy functional and critical magnetic fields anisotropy in MgB2. NATO Adv. Res. Workshop on Electron Correlation in New Materials and Nanosystems, Yalta, Ukraine, Sept. 19–23, 2005 (invited paper). K. Kukli, S. Duenas, H. Castan, H. Carcia, J. Barbolla, J. Aarik, A. Aidla, M. Ritala, M. Leskelä. Struktuuri korrastamatus ja keelutsoonisiseste elektronlõksude tihedus kõrge dielektrilise läbitavusega tahkiskihtides. XXXV Eesti Füüsikapäevad, Tartu, 22.–23. märts 2005. P. Kuusk. Relatiivsusteooria esimene sajand. Eesti filosoofia aastakonverents “Filosoofia võimus ja võimutus”, Tartu, 26.–28. mai 2005. P. Kuusk. Kaasaegse kosmoloogia standardmudel. Molekulaarbioloogia talvekool, Kääriku, 4.–6. veebr. 2005 (invited paper). P. Kuusk. Einsteini ja teiste murrangulised artiklid imepärastel aastatel 1904–1908. EFS noorte füüsikute VII sügiskool, Kääriku, 28.–30. okt. 2005 (invited paper). T. Käämbre. Participator RIXS in BeO. NordForsk Network Meeting “Synchrotron-based Electron Spectroscopy”, Aalborg and Rebild Bakker, Denmark, April 25–26, 2005. S. Lange, V. Kiisk, V. Reedo, M. Kirm, J. Aarik, I. Sildos. Luminescence of rare earth ions in metal-oxide thin films and its applications. 1st Intern. Workshop on Photoluminescence in Rare Earts: Photonics Materials and Devices (PRE’05), Trento, Italy, May 2–3, 2005. A. Lushchik, Ch. Lushchik. Role of hot electrons and hot holes in the process of defect creation and luminescence excitation by VUV radiation in wide-gap dielectrics. 13th Intern. Conf. on Radiation Effects in 172 • Biannual Report 2004/2005 156. 157. 158. 159. 160. 161. 162. 163. 164. 165. Insulators (REI-2005), Santa Fe, New Mexico, USA, Aug. 28– Sept. 02, 2005. A. Lushchik. Estonia (New countries without contract of Association). Intern. Workshop “Enlargement of the European Union: Integration of New and Recent Partners in the EURATOM Fusion Programme”, Garching, Germany, Sept. 12–13, 2005. A. Lushchik. Estonian Intern. collaboration in fusion investigations. Intern. Conf. on Fusion Investigations in Lithuania and Neighbouring Countries, Vilnius, Lithuania, Dec. 1, 2005. M. Lust, E. Realo. Radioecology in Estonia – developments. NKS-B Summary Seminar (with focus on radioecology and measurement techniques), Tartu, Estonia, Oct. 24–25, 2005 (invited paper). V. Nagirnyi. Conduction band structure in oxyanionic crystals. Intern. Conf. on Inorganic Scintillators and their Industrial Applications (SCINT2005), Alushta, Ukraine, Sept. 19–23, 2005. A. Niilisk, J. Aarik, S.N. Tkachev, M.H. Mangnani. Õhukeste oksiidkilede Ramani ja Brillouini hajumine. XXXV Eesti Füüsikapäevad, Tartu, 22.–23. märts 2005. A. Niilisk, M. Moppel, M. Pärs, I. Sildos, T. Avarmaa, R. Jaaniso, J. Aarik. Structural study of technologically important oxide thin films by micro-Raman spectroscopy. Conf. on Knowledge-based Materials and Technologies for Sustainable Chemistry (MTSC), Tallinn, Estonia, June 1–5, 2005. M. Nikl, A. Yoshikawa, T. Fukuda, A. Krasnikov, A. Vedda, K. Nejezchleb. Pr3+-doped novel single crystal scintillators. Intern. Conf. on Inorganic Scintillators and their Industrial Applications (SCINT2005), Alushta, Ukraine, Sept. 19–23, 2005 (invited paper). V. Reedo, M. Järvekülg, S. Lange, T. Tätte. Uniform aminosiloxane films for immobilization of biomolecules: a sol-gel approach. Nanopowders, Nanostructured Materials and Coatings, Tallinn, Estonia, March 17, 2005. M. Saal. Looduslik valik Multiversumis ehk universumite looduslik valik. Molekulaarbioloogia talvekool, Kääriku, 4.–6. veebr. 2005 (invited paper). M. Saal. Lokaalne Universum:kas eriline koht. Von Krahli Akadeemia, Tallinn, 22. mai 2005 (invited paper). Talks and Posters at Conferences • 173 166. M. Saal. Braanikosmoloogia ehk lühike lugu sellest, kuidas seletada Univesumi kiirenevat paisumist ja vältida algset singulaarsust. TÜ Suveülikooli raames toimunud füüsikaõpetajate seminar-konverents “Füüsika õpetamise probleemid”, Tartu, 28. juuni 2005 (invited paper). 167. M. Saal. Braanikosmoloogiast. Teadus ja religioon: Algused ja lõpud, USUS 02.075, Tartu, 23.märts 2005 (invited paper). 168. M. Saal. Erirelatiivsusteooria matemaatiline taust. Astronoomiahuviliste 10. üle-Eesti kokkutulek, Kaali, 10–15. aug. 2005 (invited paper). 169. P. Saari. How small a packet of photons can be made? 14th Intern. Laser Physics Workshop, LPHYS’05, Kyoto, Japan, July 4–8, 2005 (invited paper). 170. P. Saari. Füüsika ja turvalilisus. Akadeemiline loeng (a) TA-s, (b) TÜ aulas, (a) Tallinnas, (b) Tartu, (a) 30. märts; (b) 12. mai 2005. 171. P. Saari. How small a packet of photons can be made? Workshop on Classical and Quantum Interference, Olomouc, Czech Republic, Oct. 29–30, 2005 (invited paper). 172. A. Sherman. Incommensurate spin dynamics in underdoped cuprate perovskites. 2nd Workshop on Functional Materials, Athens, Greece, Sept. 25–30, 2005 (invited paper). 173. A. Stolovits, K. Ahn, R. K. Kremer, A. Sherman. Quantum interference of electrons in fibrous Ta4Te4Si. Conf. on Nanopowders, Nanostructured Materials and Coatings, Tallinn, Estonia, March 17, 2005. 174. A. Stolovits, R. K. Kremer, Hj. Mattausch, J.R. O'Brien, H. Okudera, X-M. Ren, A. Sherman, A. Simon. Quantum interference in Nb5–x Te4. Intern. Conf. on Transport in Interacting and Disordered Systems /(TIDS 11), Egmond aan Zee, The Netherlands, Aug. 21–26, 2005. 175. S. Zazubovich, A. Krasnikov, M. Nikl. Disintegration of exciton and defect states in PbWO4:MO,Ce crystal. Intern. Conf. on Inorganic Scintillators and their Industrial Applications (SCINT2005), Alushta, Ukraine, Sept. 19–23, 2005. 176. T. Tamm, J. Linnanto, A. Ellervee, A. Freiberg. Modeling of pessure effects on absorption spectra of solvated chlorophyll and bacteriochlorophyll molecules. Intern. Conf. Computational Methods in Science and Engineering 2005 (ICCMSE 2005), Loutraki, Greece, Oct. 21–26, 2005. 177. A. Treshchalov, A. Lissovski. VUV-VIS spectroscopic diagnostics of highcurrent pulsed volume discharge in argon. VII Intern. Conf. On Atomic 174 • Biannual Report 2004/2005 and Molecular Pulsed Lasers, Tomsk, Russia, Sept. 12–16, 2005 (invited paper). POSTER PRESENTATIONS 2005 178. L. Aarik, M. Kiisk. Samblike kasutamine bioindikaatoritena keskkonnadosimeetrias. XXV Eesti Füüsikapäevad, Tartu, 22.–23. märts 2005. 179. S. Dziarzhytski, E. Jalviste, F. Temps. Hydrogen-bonded self and water complexes of 1H-indazole. Bunsentagung 2005, Frankfurt, Germany, May 5–7, 2005. 180. A. Ellervee, J. Linnanto, T. Tamm, A. Freiberg. Solvent effects on chlorophyll and bacteriochlorophyll molecules studied by high pressuretuning spectroscopy. “Physics of Life” Workshop in Biological Physics, Copenhagen, Denmark, Aug. 21–27, 2005. 181. V. Fedoseyev. Reflection and refraction of a light beam carrying the orbital angular momentum: dynamical aspects. Intern. Conf. on Coherent and nonlinear Optics (ICONO-2005), St. Petersburg, Russia, May 11–15, 2005. 182. E. Feldbach, A. Kotlov, I. Kudryavtseva, P. Liblik, A. Lushchik, Ch. Lushchik, A. Maaroos, V. Nagirnyi, E. Vasil’chenko. Lowtemperature irradiation effects in lithium ortosilicate. 13th Intern. Conf. on Radiation Effects in Insulators (REI-2005), Santa Fe, New Mexico, USA, Aug. 28–Sept. 02, 2005. 183. E. Feldbach, J. Aarik, M. Kirm, P. Liblik, H. Mändar. Spectroscopic diagnostics of defects and traps in thin scintillating films of hafnia. Intern. Conf. on Inorganic Scintillators and their Industrial Applications (SCINT2005), Alushta, Ukraine, Sept. 19–23, 2005. 184. A. Floren, I. Kärkkänen, T. Avarmaa, R. Jaaniso. Luminescence decay in oxygen sensor materials: a general model of quenching with distributed rate constants. Eurosensors XIX, Barcelona, Spain, Sept. 11–14, 2005. 185. M. Haas. Dynamical beats of synchrotron radiation as a nuclear polariton effect. ICAME’05, Intern. Conf. on the Appl. of the Mössbauer Effect, Montpellier, France, Sept. 5–9, 2005. 186. V. Hizhnyakov, G. Benedek, I. Tehver, V. Boltrushko. Electronic transitions between dynamically stable and weakly unstable states: Optical spectra of molecules trapped in superfluid 4He droplets. AIOM2005: First Talks and Posters at Conferences • 175 187. 188. 189. 190. 191. 192. 193. 194. 195. Conf. on Advances in Optical Materials, Tucson, USA, Oct. 12–15, 2005. V. Hizhnyakov, V. Boltrushko, I. Tehver. Optical transitions in centres with soft dynamics in the excited state. PIPT2005: Second Intern. Conf. on Photo-Induced Phase Transitions: Cooperative, Non-Linear and Functional Properties, Rennes, France, May 24–28, 2005. V. Hizhnyakov. Resonance two-quantum emission by a medium with oscillating in time optical length. PIPT2005: Second Intern. Conf. on Photo-Induced Phase Transitions: Cooperative, Non-Linear and Functional Properties, Rennes, France, May 24–28, 2005. I. Jõgi, M. Laan, K. Kukli, J. Aarik. Lähteainete mõju aatomkihtsadestatud TiO2 kilede juhtivusele. XXXV Eesti Füüsikapäevad, Tartu, 22.–23. märts 2005. M. Järvekülg, V. Reedo, S. Lange, U. Mäeorg. Low-dimentional HfO2 structures elaborated by sol-gel technique. TNT2005, Oviedo, Spain, Aug. 29–Sept. 02, 2005. M. Kirm, A. Gektin, V. Nagirnyi, V. Nesterkina, K. Shimamura, N. Shiran, E. Villora. VUV spectroscopy of Ca0,65Eu0,35F2,35 single crystal. Intern. Conf. “Vacuum Ultraviolet Spectroscopy and Interaction with Condensed Matter” (VUV 2005), Irkutsk, Russia, July 18–22, 2005. V. Kisand, E. Nõmmiste, E. Kukk, A. Caló, H. Aksela, S. Aksela. Fragmentation and electronic decay of vacuum ultraviolet-excited resonant states of molecular rubidium halides. Intern. Workshop on Photoionization, Campinas, Brazil, July 27–31, 2005. P. Konsin, B. Sorkin. Off-center displacements of Ti ions in oxide ferroelectrics and a gigantic photo-induced dielectric constant of quantum paraelectric perovskite oxides in the electron-lattice theory. Second Internat. Conf. on “Photo-Induced Phase Transitions; Cooperative, Non-Linear and Functional Properties” (PIPT 2005), Rennes, France, May 24–28, 2005. P. Konsin, B. Sorkin. Doping dependence of the coherence length in the two-component model for La2–xSrxCuO4 thin films. Workshop on Weak Superconductivity (WWS’05), Bratislava, Slovak Republic, Sept. 16– 19, 2005. K. Kooser, A. Kikas, V. Kisand, T. Käämbre, A. Saar, E. Nõmmiste, I. Martinson. Resonant Inelastic X-ray Scattering at the K edge of oxygen and fluorine in insulators. NordForsk Network Meeting “Synchrotron- 176 • Biannual Report 2004/2005 196. 197. 198. 199. 200. 201. 202. 203. 204. based Electron Spectroscopy”, Aalborg and Rebild Bakker, Denmark, April 25–26, 2005. K. Kooser, A. Kikas, V. Kisand, T. Käämbre, E. Nõmmiste, I. Martinson. Participator RIXS in BeO. 18th Annual Meeting of Organisation for Users of Synchrotron Radiation at MAX-lab, Lund, Sweden, Sept. 28–29, 2005. K. Kooser, A. Kikas, T. Käämbre, V. Kisand, E. Nõmmiste, I. Martinson. Participator RIXS at Be 1s-edge in BeO. Nordic and European Summer School in Synchrotron Radiation Science “New perspectives and new sources for XUV- and X-ray Science”, Röstanga and Lund, Sweden, June 13–21, 2005. A. Krasnikov, M. Nikl, S. Zazubovich. Defects creation under UV irradiation of lead tungstate crystals. Intern. Conf. of Physics Students (ICPS’2005), Coimbra, Portugal, Aug. 11–18, 2005. A. Krasnikov, M. Nikl, S. Zazubovich. Spectroscopy of excitons in lead tungstates. IV Intern. Conf. for Students, Young Scientists and Engineers “Optics’2005”, St.Petersburg, Russia, Oct. 17–21, 2005. N. Kristoffel, T. Örd, P. Rubin. Doping dependence of cuprate in-plane coherence length in a two-component model. IV Intern. Conf. “Vortex Matter in Nanostructured Superconductors”, Crete, Greece, Sept. 3–9, 2005. N. Kristoffel. Coherence in a two-component superconductor and doping dependence of cuprate properties. NATO Adv. Res. Workshop ElectronCorrelation in New Materials and Nanosystems, Yalta, Ukraine, Sept. 19–23, 2005. K. Kukli, M. Ritala, M. Leskelä, J. Lu, J. Aarik, A. Hårsta. Atomic layer deposition of nanocrystalline metal oxide dielectric films. Finnish Chemical Congress, Helsinki, Finland, April 26–28, 2005. K. Kukli, M. Ritala, M. Leskelä, J. Lu, J. Aarik, A. Hårsta. Atomic layer deposition of nanocrystalline hafnium oxide dielectric films. Fifteenth Euoropean Conf. on Chemical Vapor Deposition (EUROCVD-15), Bochum, Germany, Sept. 4–9, 2005. An. Kuznetsov, U. Visk, A. Suisalu, A. Laisaar, J. Kikas, A. Osvet, A. Winnacker. Temperature and pressure dependence of the homogeneous width of 7F0–5D0 electronic transition in Sm2+-doped sodium borate glass. 14th Intern. Conf. on Luminescence (ICL’05), Beijing, China, July 25–29, 2005. Talks and Posters at Conferences • 177 205. A. Laisaar, A. Suisalu, An. Kuznetsov, J. Kikas. High-pressure lowtemperature spectroscopy of pyrene molecules in commensurate and incommensurate phases of biphenyl. Joint 20th AIRAPT-43rd EHPRG Intern. Conf. on High Pressure Science and Technology, Karlsruhe, Germany, June 27–July 1, 2005. 206. A. Lissovski, A. Treshchalov. Kinetics of VUV-VIS spontaneous emission of high-current pulsed volume discharge in argon. VII Intern. Conf. On Atomic and Molecular Pulsed Lasers, Tomsk, Russia, Sept. 12–16, 2005. 207. A. Lissovski, A. Treshchalov. Kinetics of Ar2* emission in high-pressure pulsed discharge. Intern. Student Conf. Development in Optics and Photonics DOP-2005, Riga, Latvia, Apr. 30–May 1, 2005. 208. A. Lissovski, A. Treshchalov. Saturation of Ar2* VUV emission output with increase of the pumping power in Ar high-pressure pulsed discharge. XXXV Eesti Füüsikapäevad, Tartu, March 22–23, 2005. 209. V. N. Makhov, M. Kirm, G.Zimmerer. Intrinsic luminescence of CsF. Intern. Conf. on Inorganic Scintillators and their Industrial Applications (SCINT2005), Alushta, Ukraine, Sept. 19–23, 2005. 210. K. Mauring, V. Krasnenko, S. Miller. Photophysics of the blue fluorescent protein. 14th Intern. Conf. on Luminescence (ICL’05), Beijing, China, July 25–29, 2005. 211. S. Neicheva, N. Shiran, M. Kirm, M. Weber, K. Shimamura. Intrinsic scintillations in LiCaAlF6 crystals. Intern. Conf. on Inorganic Scintillators and their Industrial Applications (SCINT2005), Alushta, Ukraine, Sept. 19–23, 2005. 212. E. Nõmmiste, V. Kisand, E. Kukk, A. Calo, H. Aksela, S. Aksela. Photoexcitation, -ionization and fragmentation of molecular rubidium halides. NordForsk Network Meeting “Synchrotron-based Electron Spectroscopy”, Aalborg and Rebild Bakker, Denmark, April 25–26, 2005. 213. I. Ots, H. Uibo, H. Liivat, R.-K. Loide, R. Saar. Transversely polarized beams and Z boson spin orientation in e+e– o 2 with anomalous ZZ and ZJJ couplings. The XXII Intern. Symposium on Lepton-Photon Interactions , Uppsala, Sweden, June 30–July 5, 2005. 214. V. Palm, N. Palm. Terrylene-doped biphenyl monocrystals for singlemolecule optical spectroscopy. 20th Congress of the Intern. Commission for Optics (ICO XX): Challenging Optics in Science & Technology, Changchun, China, Aug. 21–26, 2005. 178 • Biannual Report 2004/2005 215. V. Palm, N. Palm, J. Kikas. Terrylene-doped biphenyl monocrystals for single-molecule spectroscopy. 11th Intern. Workshop on “Single Molecule Spectroscopy and Ultra Sensitive Analysis in the Life Sciences”, Berlin, Germany, Sept. 21–23, 2005. 216. V. Peet, S. Shchemeljov. Sum-frequency generation and multiphoton ionization in spatially incoherent conical laser beams. XXXV Eesti Füüsikapäevad , Tartu, March 22–23, 2005 . 217. H. Pettai, V. Oja, A. Laisk, A. Freiberg. The red edge of the photosynthetic activity in green plants is at 780 nm. Gordon Conf., New Hampshire, USA, July, 2005 . 218. M. Pärs, V. Palm, J. Kikas. Selective spectroscopy of terrylene in incommensurate matrix of biphenyl. 14th Intern. Conf. on Luminescence (ICL’05), Beijing, China, July 25–29, 2005. 219. M. Pärs, V. Palm, N. Palm, J. Kikas. Single-molecule spectroscopy study of terrylene-activated monocrystalline biphenyl. Winter School in Theoretical Chemistry (“Nanophotonics”), Helsinki, Finland, Dec. 7– 9, 2005. 220. I. Rebane, R. Koch. Calculations of changes in spontaneous emission rate of a single impurity molecule in dependence on the direction of the transition dipole moment in uniaxial host crystals. 14th Intern. Conf. on Luminescence (ICL’05), Beijing, China, July 25–29, 2005. 221. I. Rebane. Different values of spontaneous emission rate of a singleimpurity molecule of pentacene in biaxial p-terphenyl crystal. 14th Intern. Conf. on Luminescence (ICL’05), Beijing, China, July 25–29, 2005. 222. V. Reedo, M. Järvekülg, S. Lange, U. Mäeorg. Preparation of lowdimentional HfO2, HfO2 and HfO2 structures by sol-gel technigue. 29th Estonian chemistry days, Tallinn, Estonia, Oct. 20–21, 2005. 223. V. Reedo, M. Järvekülg, S. Lange, T. Tätte. Preparation of lowdimentional HfO2, HfO2 and HfO2 structures by sol-gel technigue. Advanced Nanotechnologies, Testing, Production and Application of Nanoscale Materials, Primorsko, Bulgaria, June 1–7, 2005. 224. M. Saal, L. Järv, P. Kuusk. Models of the Kanno-Soda Type Brane Cosmology. Intern. Seminar „From strings to cosmic web”, Gröningen, Holland, Nov. 30–Dec. 2, 2005. 225. K. Saal, M. Plaado, I. Kink, A. Kurg, V. Kiisk, J. Kozevnikova, Aminopropyl embedded silica films as potent substrates in DNA microarray Talks and Posters at Conferences • 179 226. 227. 228. 229. 230. 231. 232. 233. 234. 235. applications. MRS Spring Meeting, San Francisco, USA, March 28 – Apr. 1, 2005. M. Selg. Reference potential approach to the inverse problem in quantum mechanics. The Nineteenth Colloquium on High Resolution Molecular Spectroscopy, Salamanca, Spain, Sept. 11–16, 2005. M. Selg. Uniform Treatment of the First and the Second Emission Continua of Rare Gases. 14th Intern. Conf. on Luminescence (ICL’05), Beijing, China, July 25–29, 2005. S. Shchemeljov, V. Peet. Multiphoton processes in spatially incoherent conical laser beams. IV Intern. Young Scientist Conf. “Optics–2005”, S.-Petersburg, Russia, Oct.17–21, 2005. A. Sherman. Incommensurate spin dynamics in underdoped cuprate perovskites. Intern. Conf. Strongly Correlated Electron Systems, Vienna, Austria, July 26–30, 2005. A. Sherman, M. Schreiber. Incommensurate spin dynamics in underdoped cuprate perovskites. 69. Jahrestagung der Deutschen Physikalischen Gesellschaft, Berlin, Germany, March 4–9, 2005. A. Stolovits, Y. Usuki, S. Zazubovich, A. Krasnikov, M. Nikl. Luminescence of the PbWO4:5% Cd crystal. XXXV Eesti Füüsikapäevad, Tartu, Estonia, March 22–23, 2005. I. Tehver. Excitation profile of CARS in multimode systems in the case of femtosecond excitation. AIOM2005: First Conf. on Advances in Optical Materials, Tucson, USA, Oct. 12–15, 2005. A. Treshchalov, A. Lissovski. Dye laser absorption probing of highcurrent pulsed volume discharge in argon. VII Intern. Conf. On Atomic and Molecular Pulsed Lasers, Tomsk, Russia, Sept. 12–16, 2005. T. Tätte, V. Jacobsen, M. Paalo, R. Branscheid, M. Kreiter, U. Maeorg, K. Saal, A. Lõhmus, I. Kink. Preparation of Sb doped SnO2 SPM tips and their use as transparent probes in STM induced light hybrid microscopy. NSTI Nanotechnology Conf. and Trade Show, Anaheim, CA, USA, May 8–12, 2005. T. Örd, N. Kristoffel, K. Rägo. Free energy functional and critical magnetic fields of a two-gap superconductor with intra- and interband interactions. IV Intern. Conf. “Vortex Matter in Nanostructural Superconductors”, Crete, Greece, Sept. 3–9, 2005. 7. DISSERTATIONS PREPARED AT THE INSTITUTE A. Kotlov, Dielectric oxyanionic crystals: band structure and electronic excitations (PhD, solid state physics). Supervisors Dr. V. Nagirnyi (Inst. of Physics, UT) and Prof. A.Lushchik (Inst. of Physics and Inst. of Materials Science, UT), Referees Dr. Vl. Makhov (Lebedev Physical Inst., Moscow) and Dr. R. Kink (Inst. of Physics, UT); maintained at the UT, 20.10.2004. M. Saal, Studies of pre-big bang and braneworld cosmology (PhD, theoretical physics). Supervisor Dr. Piret Kuusk (Inst. of Physics, UT), Referees Dr. S. Räsänen (Oxford Univ.) and Dr. E. Saar (Tartu Observatory); maintained at the UT, 03.11.2004. E. Gershkevich, Dose to bone marrow and leukaemia risk in external beam radiotherapy of prostate cancer (PhD, applied physics). Supervisors Prof. K.R.Trott (Univ. of London, Queen Mary’s College) and Dr. E. Realo (Inst. of Physics, UT), Referees Prof. W.Dörr (Technical Univ. of Dresden) and Dr. Vl. Shcherbakov (North-Estonian Regional Hospital); maintained at the UT, 06.06.2005. V. Boltrushko, Theory of vibronic transitions between states with hard and soft local phonon dynamics (MSc, theoretical physics). Supervisor Dr. V. Hizhnyakov; maintained at the UT, 09.06.2004. V. Issakhanyan, Virtual EPR spectrometer and its use on the example of MgO:Be crystal (MSc, solid state physics). Supervisors Prof L.Pung and Dr. E. Feldbach; maintained at the UT, 09.06.2004. V. Krasnenko, Photophysics of green and blue fluorescent proteins (MSc, solid state physics). Supervisor Dr. K. Mauring; maintained at the UT, 29.06.2004. Dissertations Prepared at the Institute • 181 A. Lissovski, Spectroscopic diagnostics of pulsed discharge in high-pressure rare gas mixtures (MSc, optics and spectroscopy). Supervisor Dr. A. Treshchalov; maintained at the UT, 29.06.2004. M. Pärs, Confocal microscopy for detection of single emission centres (MSc, solid state physics). Supervisor Dr. V. Palm; maintained at the UT, 09.06.2004. K. Õige, Optimisation of oxygen-sensitive layer for fibre-optical sensor (MSc, physical and analytical chemistry). Supervisors Dr. A. Suisalu and Dr. T. Avarmaa; maintained at the UT, 04.06.2004. A. Floren, Stability and heterogenity of oxygen sensitivity in polymer films doped with Pd-porphyrins (MSc, optics and spectroscopy). Supervisor Dr. R. Jaaniso; maintained at the UT, 08.06.2005. A. Kärkkänen, Photo-induced changes in electrical conductivity of carbon nanotube films in different gas environments (MSc, solid state physics). Supervisor Dr. R. Jaaniso; maintained at the UT, 08.06.2005. I. Kärkkänen, Processes of electronic energy transfer in OLED materials based on polyvinylcarbazole (MSc, optics and spectroscopy). Supervisor Dr. R. Jaaniso; maintained at the UT, 08.06.2005. S. Lange, Rare-earth ions in metal oxide films: investigation of photoexcitation mechanisms (MSc, solid state physics). Supervisor Dr. I. Sildos; maintained at the UT, 08.06.2005. R. Rammula, Atomic layer deposition study of HfO2 thin films (MSc, solid state physics). Supervisors J. Aarik and Prof. V.Sammelselg; maintained at the UT, 08.06.2005. 8. GRADUATION THESES PREPARED AT THE INSTITUTE L. Aarik, Gamma spectrometric analysis of radionuclides in lichens and soils in Tartu (BSc). Supervisor Dr. E. Realo, 2004. S. Burak, Implementation and testing of electronic registration system for highresolution Fabry-Perot interferometer (BSc). Supervisors Dr. V. Palm and M. Pärs, 2004. K. Isakar, Monte Carlo method for evaluation of self-attenuation correction factors in 210Pb gamma spectrometry (BSc). Supervisor Dr. E. Realo, 2004. M. Kleeman, Humidity reaction in optical polymer films (BSc). Supervisors Prof J. Kikas and Dr. A. Suisalu, 2004. A. Ruudi, Luminescence quenching by oxygen in polystyrene films activated with Pd-tetraphenylporphyrine: dual gas transport and two-centre model (BSc). Supervisors Dr. R. Jaaniso and Dr. T. Avarmaa, 2004. H. Valtna, Focused X wave as highly localized non-diffracting light pulse (BSc). Supervisors Prof. P. Saari and Dr. K. Reivelt, 2004. I. Bljahhin, Construction of optical diffraction masks (BSc). Supervisor Dr. H. Mändar, 2005. L. Feklistova, Magnetical and optical information storages and interfaces (BSc). Supervisor Dr. E. Nõmmiste, 2005. S. Galayev, Spectral transformers for display panels (PDP) (BSc). Supervisors Prof. A. Lushchik and Dr. A. Maaroos, 2005. S. Hödemann, Light scattering in tempered glass (BSc). Supervisors Dr. A. Suisalu and Prof. J. Kikas, 2005. M. Järvekülg, Preparation of hafnia materials from hafnium4butoxide by solgel (BSc). Supervisors V. Reedo and Dr. U. Mäeorg, 2005. A. Jürgenson, The Christiansen filter (BSc). Supervisors Prof. J. Kikas and Dr. A. Suisalu, 2005. Graduation Theses Prepared at the Institute • 183 K. Kasemets, Organically modified titanium oxide films as substrates for immobilization of aminated DNA (BSc). Supervisors S. Mäeorg and K. Saal, 2005. M. Kodu, Laser deposition of PbZrO3 and SrRuO3 thin films (BSc). Supervisor Dr. R. Jaaniso, 2005. S. Leinberg, High vacuum AFM: problems and solutions (BSc). Supervisor Dr. R. Lõhmus. A. Lukner, Influence of ambient gaseous environment to the impurities emission in Sm3+-doped TiO2 thin films: possible use in gas sensing (BSc). Supervisors V. Kiisk and Dr. I. Sildos, 2005. S. Miller, Properties of the excited states of the blue fluorescent protein (BSc). Supervisor Dr. K. Mauring, 2005. M. Moppel, Development of confocal microscope for Raman and luminescence measurements (BSc). Supervisors M. Pärs and Dr. I. Sildos, 2005. R. Pärna, Atomic layer deposition of chromium(III)oxide thin films (BSc). Supervisors Dr. A. Niilisk, A. Tarre and Dr. A. Rosental, 2005. A. Ragni, Using of interface card NI6259 in physical experiments (BSc). Supervisor Dr. E. Nõmmiste, 2005. R. Sarakvasha, Properties of electronic excitations in CdWO4:Mo and CdMoO4 crystals (BSc). Supervisors Dr. V. Nagirnyi and Dr. A. Kotlov, 2005. M. Tamm, Luminescence study of TiO2 thin films doped with Eu3+ and Er3+ ions (BSc). Supervisors S. Lange and Dr. I. Sildos, 2005. M. Timusk, Indoor gamma dose (BSc). Supervisor Dr. E. Realo, 2005. U. Visk, Phase and energy relaxation of electron transition 7F0–5D0 of Sm2+ ion (BSc). Supervisor Dr. A. Suisalu, 2005. 9. SCIENTIFIC MEETINGS ORGANIZED International Meeting of the NORFA financed network “Synchrotron-based electron spectroscopy”; Tartu, Estonia, March 15, 2004; 20 participants from Estonia, Norway, Sweden and Denmark. Organizing – A. Kikas. International Synchrotron Radiation Summer School; Kääriku, Estonia, June 2–5, 2004; 39 participants from Estonia, Finland, Sweden and Hungary. Organizing Committee – E. Nõmmiste (Inst. of Physics, UT) and E. Kukk (Univ. of Turku). 4th International Conference on Advanced Optical Materials and Devices (AOMD-4); Tartu, Estonia, July 7–10, 2004; 95 participants from Estonia, Finland, France, Germany, Israel, Latvia, Lithuania, Poland, Russia, Sweden and USA. Organizing Committee – A. Gerst, R. Jaaniso, A. Rosental, I. Sildos, L. Sildos, A. Tarre, I. Tehver. 15th International Conference on Insulating Materials (ICDIM-2004); Riga, Latvia, July 11–16, 2004; 235 participants from 30 countries. Organized together with Institute of Solid State Physics, Univ. of Latvia. Members of Organizing Committee from Institute of Physics – A. Lushchik (cochairman), T. Kärner, V. Nagirnyi and S. Zazubovich. Guest Editors of Materials ICDIM-2004 (Phys. status solidi (c)) – A. Lushchik, S. Zazubovich and I. Tale. 6th Young Physicist’s Autumn School, organized by the Estonian Physical Society; Kääriku, Estonia, Oct. 8–10, 2004; 65 participants. Organizing Committee – M. Saal, A. Hektor, A. Kikas. Scientific Meetings Organized • 185 7th Young Physicist’s Autumn School, organized by the Estonian Physical Society; Kääriku, Estonia, Oct. 28–30, 2005; 87 participants. Organizing Committee – A. Hektor, A. Kuusk, M. Müntel, K. Reivelt, M. Saal. Exhibition in nuclear fusion “Expo Fusion”; Tartu, Estonia, Nov. 8–14, 2005; about 5000 visitors; Tallinn, Estonia, Nov. 21–28, 2005; about 3000 visitors. Main organizer – M. Kiisk. 10. VISITS TO RESEARCH CENTRES ABROAD 2004 A. Aabloo – French Atomic Energy Agency (France), 26.04.–30.04.04. A. Anijalg, – University of Latvia (Latvia9, 20.07.–22.07.04. S. Dolgov – Lund University, MAX-Lab (Sweden), 08.02.–16.02.04, 07.11.–21.11.04. E. Feldbach – Lund University, MAX-Lab (Sweden), 08.02.–16.02.04, 07.11.–21.11.04. A. Freiberg – Institute of Physics, Vilnius (Lithuania), 14.11.–20.11.04. M. Haas – University of Luebeck, Institute of Physics (Germany), 22.11.– 17.12.04. V. Hizhnyakov – University of Milan, University of Bicocca (Italy), 02.02.– 17.02.04, 22.02.–11.03.04. V. Hizhnyakov – University of Stuttgart, Dept. of Theoretical Physics (Germany), 17.02.–22.02.04. V. Hizhnyakov – Max-Planck Institute, Göttingen, Brandenburg Technical University (Germany), 26.10.–31.10.04. V. Hizhnyakov – Brussels University (Belgium), 28.11.–01.12.04. R. Jaaniso – University of Latvia, Institute of Solid State Physics (Latvia) E. Jalviste – University of Kiel, Institute of Physical Chemistry (Germany), 04.09.–30.12.04. M. Kiisk – Studsvik Ltd. (Sweden), 09.11.–12.11.04. A. Kikas – Lund University, MAX-Lab (Sweden), 01.02.–08.02.04, 15.02.– 23.02.04. A. Kikas –Mulhouse (France), 25.03.–28.03.04. A. Kikas – University of Hamburg, HASYLAB (Germany), 18.05.– 26.05.04. Visits to Research Centres Abroad • 187 M. Kirm – University of Hamburg, HASYLAB (Germany), 31.05.– 07.06.04, 03.12.–13.12.04. M. Kirm – University of Latvia, Institute of Solid State Physics (Latvia), 20.10.–21.10.04. M. Kirm – BESSY, Berlin (Germany), 31.10.–07.11.04. V. Kisand – Lund University, MAX-Lab (Sweden), 25.01.–09.02.04, 15.02.–24.02.04, 19.05.–24.05.04, 27.06.–05.07.04, 11.10.– 18.10.04. V. Kisand – University of Hamburg, HASYLAB (Germany), 18.04.– 29.04.04, 18.05.–26.05.04. V. Kisand – BESSY, Berlin (Germany), 31.10.–07.11.04. K. Kooser – Lund University, MAX-Lab (Sweden), 01.02.–08.02.04, 15.02.–23.02.04, 11.10.–18.10.04. K. Kooser – University of Aarhus (Denmark), 18.10.–07.11.04. A. Kotlov – University of Hamburg, HASYLAB (Germany), 25.01.– 02.02.04, 31.05.–07.06.04, 08.12.–15.12.04. A. Kotlov – Lund University (Sweden), 07.11.–21.11.04. A. Krasnikov – Institute of Physics, Acad. Sci. of Czech Republic (Czech Republic), 06.09.04.–06.01.05. T. Käämbre – Lund University, MAX-Lab (Sweden), 26.01.–31.01.04, 01.02.–08.02.04, 15.02.–23.02.04, 12.04.–18.04.04, 20.05.– 30.05.04, 25.06.–29.06.04, 27.07.–31.07.04, 06.09.–10.09.04, 11.10.–18.10.04, 15.11.–26.11.04, 13.12.–17.12.04. T. Käämbre – University of Hamburg, HASYLAB (Germany), 18.05.– 26.05.04. S. Lange – University of Hamburg, HASYLAB (Germany), 26.04.– 02.05.04. A. Lukner – University of Hamburg, HASYLAB (Germany), 26.04.– 02.05.04. A. Lushchik – University of Hamburg, HASYLAB (Germany), 25.01.– 02.02.04, 31.05.–07.06.04, 08.12.–15.12.04. A. Lushchik – University of Latvia, Institute of Solid State Physics (Latvia), 14.04.–16.04.04. A. Lushchik – St.Petersburg State Technological University, Vavilov GOI Science Center (Russia), 18.11.–23.11.04. Ch. Lushchik – St.Petersburg State University, Physical-Technical Institute (Russia), 20.11.–24.11.04. 188 • Biannual Report 2004/2005 A. Lõhmus – Soome, Helsinki University of Technology (Finland), 18.02.– 20.02.04. A. Lõhmus – Helsinki University of Technology (Finland), 11.08.– 13.08.04. A. Lõhmus – University of Latvia, Institute of Physics (Latvia), 27.05.2004. A. Lõhmus – Brussels (Belgium), 26.06.–29.06.04. A. Lõhmus – University of Latvia, Institute of Chemical Physics (Latvia), 31.08.2004. A. Lõhmus – University of Latvia, Institute of Chemical Physics (Latvia), 18.11.04, 29.12.04. R. Lõhmus – University of Latvia, Institute of Physics (Latvia), 03.02.– 04.02.04. R. Lõhmus – University of Latvia, Institute of Physics (Latvia), 27.05.2004. R. Lõhmus – Lund University, MAX-Lab and Chalmers University (Sweden), University of Trondheim, Dept. of Applied Physics (Norway), 11.06.–21.06.04. R. Lõhmus – University of Latvia, Institute of Chemical Physics (Latvia), 18.11.2004. M. Moppel – University of Uppsala, Department of Chemistry (Sweden), 06.12.–12.12.04. H. Mändar – University of Konstanz, Laboratory of Solid State Chemistry (Germany), 21.09.–24.20.04. V. Nagirnyi – University of Hamburg, HASYLAB (Germany), 25.01.– 02.02.04, 31.05.–07.06.04, 08.12.–15.12.04. V. Nagirnyi – Rootsi, Lund University, MAX-Lab (Sweden), 08.02.– 16.02.04, 07.11.–21.11.04. V. Nagirnyi – University of Latvia, Institute of Solid State Physics (Latvia), 28.06.–29.06.04. V. Nagirnyi – Institute of Solid State Physics and Optics (Hungary), 13.09.–26.09.04. E. Nõmmiste – Lund University, MAX-Lab (Sweden), 25.01.–09.02.04. E. Nõmmiste – Prague (Czech Republic), 22.05.–27.05.04. E. Nõmmiste – University of Latvia, Institute of Solid State Physics (Latvia), 20.10.–21.10.04. E. Nõmmiste – University of Oulu (Finland), 21.10.–23.10.04. M. Pärs – University of Uppsala, Department of Chemistry (Sweden), 20.09.–27.09.04, 06.12.–12.12.04. Visits to Research Centres Abroad • 189 E. Realo – London (Great Britain), 28.06.2004. E. Realo – Paris (France), 20.10.–24.10.04. E. Realo – Brussels (Belgium), 11.02.–13.02.04, 26.04.–28.04.04, 30.06.04. K. Rebane – University of St.Petersburg (Russia), 20.05.–27.05.04. K. Rebane – University of Stuttgart (Germany), 31.10.–05.11.04. K. Reivelt – Max-Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Berlin (Germany), 04.07.–08.07.04. K. Reivelt – Mulhouse (France), 14.10.–17.10.04. R. Ruus – University of Oulu (Finland), 06.06.–03.07.04. K. Saal – Lund University, Chalmers University, University of Trondheim, MAX-Lab, Dept. of Applied Physics (Sweden Norway), 11.06.– 21.06.04. P. Saari – Max-Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Berlin (Germany), 04.07.–08.07.04. I. Sildos – University of Erlangen, University of Regensburg, Institute of Materials Research, Institute of Physics (Germany), 03.02.–11.02.04. I. Sildos – Institute of General Physics, Moscow (Russia), 28.09.–06.10.04. A. Stolovits – Max-Planck Institute for Solid State Research (Germany), 06.09.–02.12.04. A. Sherman – Technical University of Chemnitz, Institute of Theoretical Physics (Germany), 24.06.–03.08.04. S. Zazubovich – Institute of Physics, Czech Acad. Sci., Laboratory of Luminescence (Czech Republic), 06.09.–19.09.04. S. Zazubovich – Institute of Applied Physics, Laboratory of Laser Spectroscopy (Italy), 25.09.03.–24.03.04. A. Tarre – University of Uppsala, The Ångström Laboratory (Sweden), 20.09.–03.10.04. A. Treshchalov – Institute of Thermonuclear Research, Moscow (Russia), 14.06.–19.06.04. 2005 V. Babin – University of Hamburg, DESY, HASYLAB (Germany), 21.01.– 31.01.05; 25.02.–07.03.05; 08.06.–22.06.05; 24.10.–02.11.05; 12.12.–14.12.05. 190 • Biannual Report 2004/2005 V. Babin – Institute of Geochemistry, Russian Acad. Sci. (Russia), 17.07.– 28.07.05. V. Babin – University of Utrecht, Department of Condensed Matter and Interfaces (The Netherlands), 17.05.–22.05.05. V. Babin – Philips Research (The Netherlands), 21.08.–25.08.05. V. Boltrushko – University of St.Petersburg, (Russia), 20.11.–29.11.05. V. Boltrushko – University of Helsinki, Dept. of Chemistry (Finland), 06.12.–09.12.05. E. Feldbach – Lund University, MAX-Lab (Sweden), 20.02.–27.02.05. E. Feldbach – University of Hamburg, DESY, HASYLAB (Germany), 28.02.–07.03.05; 06.06.–17.06.05; 18.07.–25.07.05; 12.12.–14.12.05 E. Feldbach – The Saclay Laser-Matter Interaction Center (France), 04.10.– 20.10.05. A. Freiberg – Umeå University (Sweden), 12.06.–16.06.05. V. Hizhnyakov – Cornell University (USA), 19.03.–26.03.05. V. Hizhnyakov – University of Brussels, INTAS (Belgium), 08.03.– 11.03.05; 15.11.–19.11.05 K. Isakar – European Physical Society, (France), 12.01.–16.01.05. K. Isakar – Institute for Transuranium Elements (Germany), 14.06.– 18.06.05. K. Isakar – CERN (Switzerland), 24.05.–28.05.05. K. Isakar – Jozef Stefan Institute (Slovenia), 13.09.–19.09.05. V. Issakhanyan – University College London (Great Britain), 09.05.– 08.07.05. L. Järv – Helsinki Institute of Physics (Finland), 13.02.–17.02.05. L. Järv – Institute of Adv. Studies (Israel), 27.12.05–09.01.06. T. Käämbre – University of Hamburg, DESY, HASYLAB (Germany), 13.02.–21.02.05; T. Käämbre – Lund University, MAX-Lab (Sweden), 06.02.–12.02.05; 20.11.–24.11.05; 05.12.–19.12.05. H. Kaasik – University of Helsinki, Dept. of Chemistry (Finland), 06.12.– 10.12.05. M. Kiisk – Institute for Transuranium Elements (Germany), 14.06.– 18.06.05. M. Kiisk – Jozef Stefan Institute (Slovenia), 13.09.–19.09.05. V. Kiisk – Ångström Laboratory (Sweden), 09.10.–14.10.05. Visits to Research Centres Abroad • 191 A. Kikas – University of Hamburg, DESY, HASYLAB (Germany), 06.02.– 14.02.05; A. Kikas – Lund University, MAX-Lab (Sweden), 15.02.–21.02.05; 13.04.– 18.04.05; 13.06.–20.06.05; 27.09.–30.09.05. A. Kikas – Aalborg University (Denmark), 24.04.–27.04.05. I. Kink – Lund University, MAX-Lab (Sweden), 07.02.–12.02.05.15.03.– 16.03.05; I. Kink – European Commission (Belgium), 17.02.–19.02.05; 18.05.– 20.05.05; 10.10.–11.10.05. I. Kink – HUT (Finland), 08.06.05. I. Kink – Zernike Group (The Netherlands), 02.05.–15.05.05. R. Kink – Lund University, MAX-Lab (Sweden), 06.02.–20.02.05. M. Kirm – University of Hamburg, DESY, HASYLAB (Germany), 28.02.– 07.03.05; 06.06.–22.06.05; 18.07.–22.07.05; 12.12.–14.12.05. M. Kirm – Consultative Committee for the Euroatom Specific Research and Training Programme in the field of Nuclear Energy (Fusion, CCE-FU) (Belgium), 06.06.–07.06.05. M. Kirm – VDI/DE-IT Innovation + Technik GmbH Dept. Innovation Europe (Germany), 31.08.–02.09.05; 28.11.–29.11.05. M. Kirm – The Saclay Laser-Matter Interaction Center (France), 04.10.– 13.10.05. M. Kirm – CCE-FU, CEA (France), 10.11.–12.11.05. V. Kisand – Lund University, MAX-Lab (Sweden), 13.02.–20.02.05; 08.05.–23.05.05; 15.06.–27.06.05; 27.09.–30.09.05. V. Kisand – Aalborg University (Denmark), 24.04.–26.04.05. V. Kisand – Synchrotron Radiation Center (Brazil), 25.07.–07.08.05. K. Kooser – University of Hamburg, DESY, HASYLAB (Germany), 06.02.– 12.02.05. K. Kooser – Lund University, MAX-Lab (Sweden), 13.02.–21.02.05; 08.05.–23.05.05; 13.06.–21.06.05; 14.11.–24.11.05; 07.12.– 19.12.05. K. Kooser – Aarhus University, Laboratory of Synchrotron Radiation ASTRID (Denmark), 31.08.–26.09.05. A. Kotlov – University of Hamburg, DESY, HASYLAB (Germany), 24.01.– 31.01.05; 28.02.–07.03.05; 20.03.–29.03.05; 24.10.–31.10.05. A. Kotlov – Lund University, MAX-Lab (Sweden), 20.02.–27.02.05; 27.06.–04.07.05. 192 • Biannual Report 2004/2005 S. Lange – University of Hamburg, DESY, HASYLAB (Germany), 28.02.– 07.03.05. S. Lange – Ångström Laboratory (Sweden), 09.10.–14.10.05; 12.12.– 13.12.05. A. Lissovski – University of Uppsala, Institute of Physics (Sweden), 26.09.– 08.10.05. A. Lissovski – Physikzentrum Bad Honnef (Germany), 08.10.–16.10.05. A. Lõhmus – Acad. Sci. of Ukraine, Institute of Materials Research (Ukraine), 04.03.–07.03.05. A. Lõhmus – Helsinki University of Technology (Finland), 07.06.– 08.06.05; 21.06.–22.06.05; 17.08.–18.08.05. A. Lõhmus – Latvian State University, Institute of Chemical Physics (Latvia), 12.09.05. R. Lõhmus – Latvian State University (Latvia), 31.01.05. R. Lõhmus – Latvian State University, Institute of Chemical Physics (Latvia), 09.12.–13.12.05. R. Lõhmus – Zernike Group (The Netherlands), 14.03.–23.03.05; 18.04.– 15.05.05. R. Lõhmus – Helsinki University of Technology (Finland), 17.11.– 20.11.05. R. Lõhmus – K-Tek (USA), 08.09.–11.09.05. A. Lushchik – University of Hamburg, DESY, HASYLAB (Germany), 20.03.–28.03.05; 24.10.–31.10.05. A. Lushchik – EFDA Meeting (Germany), 11.09.–14.09.05. A. Moorits – Helsinki University of Technology (Finland), 27.10.– 28.10.05. M. Moppel – Institute of Physics (Ukraine), 13.06.–17.06.05. V. Nagirnyi – Lund University, MAX-Lab (Sweden), 20.02.–28.02.05; 27.06.–04.07.05 V. Nagirnyi – Institute for Solid State Physics and Optics, Hungarian Acad. Sci. (Hungary), 24.04.–01.05.05. V. Nagirnyi – University of Hamburg, DESY, HASYLAB (Germany), 20.203.–29.03.05; 24.10.–31.10.05. V. Nagirnyi – The Saclay Laser-Matter Interaction Center (France), 04.10.– 20.10.05. E. Nõmmiste – Aalborg University (Denmark), 24.04.–27.04.05. E. Nõmmiste – Finnish Acad. Sci. (Finland)12.01.–13.01.05. Visits to Research Centres Abroad • 193 E. Nõmmiste – Lund University, MAX-Lab (Sweden), 08.05.–17.05.05; 15.06.–27.06.05; 27.09.–29.09.05; 13.11.–20.11.05. E. Nõmmiste – University of Turku (Finland), 06.10.–07.10.05. E. Nõmmiste – Synchrotron Radiation Center (Brazil), 25.07.–07.08.05. V. Palm – Lund Laser Center (Sweden), 03.04.–14.04.05; 24.04.–05.05.05. V. Palm – Munich Trade Fairs International (Germany), 14.06.–16.06.05. M. Pärs – Lund Laser Center (Sweden), 03.04.–14.04.05; 24.04.–05.05.05. M. Pärs – Helsinki University, Dept. of Chemistry (Finland), 06.12.– 09.12.05. M. Pärs – Andor Technology (Ireland), 12.12.–15.12.05. M. Rätsep – Han-Meitner-Institut (Germany), 27.04.–01.05.05. E. Realo – Consultative Committee for the Euroatom Specific Research and Training Programme in the field of Nuclear Energy (Fusion, CCE-FU) (Belgium), 26.01.–28.01.05; 07.03.–09.03.05. E. Realo – EURATOM Scientific and Technical Committee (STC) (Belgium), 04.04.–07.04.05. E. Realo – EUROATOM Scientific and Technical Committee (STC) (Germany), 23.10.–26.10.05. K. Rebane – University of Helsinki (Finland), 17.04.–01.05.05. K. Rebane – Russian Acad. Sci., Ioffe Institute of Physics (Russia), 15.05.– 29.05.05. K. Rebane – CERN, (Switzerland), University of Stuttgart (Germany), 26.10.–08.11.05. V. Reedo – NENAMAT Committee (Bulgaria), 31.05.–07.06.05. R. Ruus – University of Turku (Finland), 01.11.–24.12.05. M. Saal – Summer School “The Invisible Universe: Dark Matter and Dark Energy”, Karfas (Greece), 23.09.–05.10.05. H. Salujärv – Umeå University (Sweden), 14.11.–19.11.05. A. Sherman – Technical University of Berlin, Technical University of Chemnitz (Germany), 03.03.–29.03.05; 23.11.–30.11.05. I. Sildos – University of Regensburg (Germany), 03.05.–08.05.05. I. Sildos – Institute of Physical Technology (Russia), 28.07.–31.07.05. I. Sildos – Amsterdam University, Van-der-Waals Institute; Utrecht University, Debye Institute (The Netherlands), 10.10.–15.10.05. I. Sildos – Institute of General Physics (Russia), 09.12.–15.12.05. A. Stolovits – Max Planck Institute for Solid State Research (Germany), 20.06.–01.08.05; 18.08.–13.10.05. 194 • Biannual Report 2004/2005 A. Tarre – ELFA (Sweden), 01.02.–03.03.05. A. Tarre – Ångström Laboratory (Sweden), 09.10.–17.10.05. T. Tätte – Adlershof Science Center (Germany), 09.02.–12.02.05. T. Tätte – University of Padova (Italy), 15.05.–29.05.05. K. Timpmann – Umeå University (Sweden), 12.06.–16.06.05; 14.11.– 19.11.05. A. Treshchalov – Uppsala University, Dept. of Physics (Sweden), 25.09.– 07.10.05. J. Vahi – Helsinki University of Technology (Finland), 27.10.–28.10.05; 07.11.–18.11.05. A. Vaigu – European Physical Society (France), 12.01.–16.01.2005. H. Valtna – European Physical Society (France), 12.01.–16.01.2005. S. Vlassov – Latvian State University, Institute of Chemical Physics (Latvia), 09.12.05. S. Zazubovich – Institute of Physics, Lab of Luminescence (Czech Republic), 17.04.–29.204.05. 11. VISITORS 2004 T. H. Andersen – University of Southern Denmark (Denmark), 15.03.04. E. Arakelova – State Engineering University of Armenia (Armenia), 26.05.– 27.05.04. A. Beitlerova – Institute of Physics, Acad. Sci. CR, Laboratory of Luminescence (Czech Republic), 19.09.–03.10.04. J. Bohr – Danish University of Technology (Denmark), 30.09.04. K. J. Borve – University of Bergen, Dept. of Chemistry (Norway), 15.03.04. G. Damazyan – State Engineering University of Armenia (Armenia), 26.05.–27.05.04. B. Green – European Commission (Belgium), 25.10.–26.10.04. P. Hoyer – University of Helsinki, Faculty of Science, Dept. of Physical Sciences, High Energy Physics Division (Finland), 25.02.–28.02.04. S. Karttunen – Association Euroatom-Tekes, VTT Processes (Finland), 13.02.–14.02.04. A. Kechiantz – State Engineering University of Armenia (Armenia), 26.05.– 27.05.04. R. Kremer – Max-Planck Institute for Solid State Research, Stuttgart (Germany), 10.06.–19.06.04. A. Krumins – University of Latvia, Institute of Solid State Physics (Latvia), 09.12.04. M. Ladadweh – University of Bergen, Dept. of Chemistry (Norway), 15.03.04. J. Linnanto – University of Jyväskylä, Dept. of Chemistry (Finland), 03.12.–06.12.04. E. Mihokova – Institute of Physics, Acad. Sci. CR, Laboratory of Luminescence (Czech Republic), 19.09.–26.09.04. 196 • Biannual Report 2004/2005 N. Mironova – Institute of Solid State Physics, Riga (Latvia), 05.07.– 09.07.04. J. Onsgaard – Aalborg University, Institute of Physics (Denmark), 15.03.04. A. Osvet – University of Erlangen, Institute of Materials Science (Germany), 25.03.04. J. Pieper – Humboldt University (Germany), 07.06.–11.06.04. V. Pokropivny – Institute for Problems of Materials Science of NAS, Kiev (Ukraine), 06.08.–05.09.04. J. Prikulis – University of Latvia, Institute of Chemical Physics (Latvia), 03.10.–06.11.04. A. Sternberg – University of Latvia, Institute of Solid State Physics (Latvia), 09.12.04. S. Svensson – University of Uppsala (Sweden), 15.03.04. E. D. Trifonov – St.Petersburg Pedagogical University (Russia), 13.10.– 16.10.04. M. Wagner – University of Stuttgart, Institute of Theoretical Physics (Germany), 29.09.04. G. Öhrwall – University of Uppsala (Sweden), 15.03.04. A. Watterich – Institute of Solid State Physics and Optics, Hungarian Acad. Sci. (Hungary), 16.07.–22.07.04. 2005 S. Aksela – University of Oulu, Lab of Electron Spectroscopy (Finland), 27.12.05. H. Aksela – University of Oulu, Lab of Electron Spectroscopy (Finland), 27.12.05. G. Corradi – Institute for Solid State Physics and Optics, Hungarian Acad. Sci. (Hungary), 29.08.–11.09.05. D. Ivanov – Institute of Chemistry, Dept. of Surface and Interface (France), 02.06.05. R. K. Kremer – Max Planck Institute for Solid State Research (Germany), 03.06.–10.06.05. E. Kukk – University of Oulu, Dept. of Physical Sciences (Finland), 27.12.05. J. Linnanto – University of Jyväskylä, Dept. of Chemistry (Finland), 21.12.–23.12.05 Visitors • 197 I. Martinson – Lund University (Sweden), 24.11.–27.11.05. J. Mares – Institute of Physics, Czech Acad. Sci. (Czech Republic), 10.05.– 24.05.05. A. K. Müller – University of Zürich, Institute of Physics (Switzerland), 05.06.–09.06.05. J. Nilsson – Hasselblad Foundation (Sweden), 24.11.–26.11.05. V. Pokropivny – Institute of Materials Research (Ukraine), 06.08.– 20.08.05. T. Saarsoo – Helsinki Valve and Fitting OY (Finland), 29.12.05. K. Schwartz – Gesellschaft für Schwerionenforschung (GSI) (Germany), 01.11.–08.11.05. G. Seibold – Brandenburg Technical University (Germany), 06.06.– 11.06.05. D. Smith – University of Southhampton, School of Physics and Astronomy (Great Britain), 28.06.05. N. Solovieva – Institute of Physics, Czech Acad. Sci. (Czech Republic), 10.05.–24.05.05. Ch. Söderlund – Vacuumservice OY (Finland), 29.04.05. A. Zurita – European Commission, DG Research, Directorate J, Energy Unit J.6 (Belgium), 07.11.–09.11.05. K. Tanskanen – Kata Electronics OY (Finland), 11.07.–12.07.05. 12. PEDAGOGICAL ACTIVITIES 12.1. Lecture courses at the University of Tartu J. Aarik – FKMF.01.107 Thin-film technology (obligatory subject, 2 credits; 2004) J. Aarik – FKMF.01.043 Optoelectronics (elective subject, 2 credits; 2004) J. Aarik – FKMF.01.044 Technology of electronic devices (elective subject, 1 credit, 2004) V. Babin, H. Kaasik, A. Tarre – Fundamentals of physical measurements (obligatory subject, 2 credits; 2005) A. Freiberg – BGMR.07.023 Biological physics (obligatory subject, 4 credits; 2004, 2005) V. Hizhnyakov – FKTF.03.006 Quantum mechanics I (obligatory subject, 4.5 credits; 2004, 2005) V. Hizhnyakov – FKTF.03.017 Fundamentals of quantum mechanics (obligatory subject, 2 credits; 2005) V. Hizhnyakov – FKTF.04.012 Theoretical physics (obligatory subject, 4 credits, 2005) R. Jaaniso – FKMF.01.087 Materials technologies (obligatory subject, 2 credits; 2004) R. Jaaniso – FKMF.01.110 Physical materials technologies (obligatory subject, 2 credits; 2004, 2005) R. Jaaniso – FKMF.01.132 Nanotechnologies (elective subject, 2 credits; 2004, 2005) A. Kikas – FKMF.02.014 Interaction of ionizing radiation with matter (elective subject, 2 credits; 2004) A. Kikas, M. Kirm, T. Kärner – FKEF.01.037 Experimental methods in materials physics (obligatory subject, 4 credits; 2005) Pedagogical Activities • 199 R. Kink – Biological effects of the laser light. Types of lasers and fibers. Lasers in the therapy and surgery (a part of FKEF.02.028 Biomedical instrumentation and methods, 4 credits) (elective subject; 2004, 2005) V. Korrovits – FKEF.04.013 Experimental cryoengineering (elective subject, 2 credits; 2004, 2005) V. Korrovits, A. Kotlov, I. Kudryavtseva, K. Mauring, R. Koch – FKEF.02.105 Electrical measurements (practical training; obligatory subject, 2 credits; 2005) P. Kuusk – ELFI.03.002 – Philosophical fundamentals of natural sciences (obligatory subject, 2 credits; 2004, 2005) P. Kuusk – ELFI.03.003 – Philosophy of time and space (selected topics) (elective and optional subject, 2 credits; 2004, 2005) T. Kärner – FKEF.02.016 Magnetic resonance methods in materials science (elective subject, 2 credits; 2005) A. Lushchik – FKMF.02.013 Dosimetric and scintillation materials (obligatory subject, 2 credits; 2004, 2005) A. Lushchik – FKMF.02.017 Physics of solid materials (elective subject, 4 credits, 2004) A. Lushchik – FKEF.01.012 Spectroscopy I (obligatory subject, 1 credit; 2004) H. Mändar – FKMF.02.001 X-ray diffraction (obligatory subject, 1 credit; 2004, 2005) H. Mändar – FKMF.02.009 X-ray crystal structure analysis (elective subject, 2 credits; 2004) H. Mändar – FKMF.02.010 3D virtual modelling of physical experimental equipment (elective subject, 1 credit; 2005) E. Nõmmiste – FKEF.02.071 Hardware components (obligatory subject, 4 credits; 2004, 2005) I. Ots, R. Saar – FKTF.04.013 Physics of elementary particles (elective subject, 4 credits; 2005) E. Realo – FKKF.03.001 Dosimetry in environment and radiation protection I (obligatory/elective subject, 3 credits; 2004, 2005) E. Realo – FKKF.03.073 Dosimetry in environment and radiation protection (obligatory/elective subject, 2 credits; 2005) E. Realo – FKKF.03.075 Dosimetry in environment and radiation protection II (elective subject, 4 credits; 2005) 200 • Biannual Report 2004/2005 I. Renge – FKMF.01.113 Fotoactive materials (elective subject, 2 credits; 2004, 2005) K. Saal, T. Tätte – FKOK.01.046 Organic chemistry (practical works; obligatory subject, 3 credits; 2004) P. Saari – FKEF.04.007 Electricity and magnetism (obligatory subject, 4 credits; 2004, 2005) P. Saari – FKEF.04.008 Fundamentals of signals and systems I (obligatory/elective subject, 2 credits; 2004, 2005) P. Saari – FKEF.04.009 Fundamentals of signals and systems II (obligatory/elective subject, 2 credits; 2004, 2005) H. Siimon – FKMF.01.102 Structure of matter I (practical works; obligatory subject, 2 credits; 2004, 2005) H. Siimon, T. Avarmaa, A. Floren, V. Kiisk, I. Kärkkänen, R. Rammula, M. Pärs – FKMF.02.011 Structure of matter II (practical works, obligatory/elective subject, 4 credits; 2005) H. Siimon – FKMF.01.149 Materials physics. Mechanics and heat (practical works I; obligatory subject, 4 credits; 2005) H. Siimon, J. Kikas – FKMF.01.109 Physics of specific materials (obligatory subject, 2 credits; 2005) H. Siimon, J. Kikas – FKMF.01.069 Computer simulations (elective subject, 2 credits; 2005) H. Siimon, J. Kikas – FKMF.01.101 Structure of matter (seminars; obligatory subject, 4 credits; 2005) I. Sildos, V. Kiisk – FKMF.01.143 Spectroscopy II (elective subject, 1 credit; 2005) 12.2. Supevising of PhD theses (postgraduates (doctoral level) of the University of Tartu) J. Aarik V. Hizhnyakov R. Jaaniso A. Kikas N. Kristoffel P. Kuusk U. R. Rammula (2005) V. Boltrushko (2005) T. Jantson (2004), A. Floren (2005), A. Kärkkänen (2005), I. Kärkkänen (2005) K. Kooser (2004, 2005) K. Rägo (2004) Ivask (2004, 2005) Pedagogical Activities • 201 T. Kärner A. Lushchik A. Lõhmus K. Mauring V. Nagirnyi V. Palm V. Peet E. Realo P. Saari I. Sildos A. Treshchalov S. Zazubovich S. Nakonechnyi (2004, 2005), V. Issakhanyan (2004, 2005) A. Kotlov (2004), S. Nakonechnyi (2004, 2005), V. Issakhanyan (2004, 2005) K. Saal (2004, 2005), T. Tätte (2004, 2005), V. Reedo (2004, 2005) V. Krasnenko (2004, 2005) A. Kotlov (2004) M. Pärs (2005) S. Shchemelev (2004, 2005) E. Gershkevich (2004), T. Sisask (2004, 2005) J. Pruulmann (2004, 2005) V. Kiisk (2004, 2005), S. Lange (2005) A. Lissovski (2004, 2005) A. Krasnikov (2004, 2005) 12.3. Supervising of MSc theses (postgraduates (master level) of the University of Tartu J. Aarik T. Avarmaa V. Fedoseyev A. Freiberg V. Hizhnyakov R. Jaaniso M. Kiisk I. Kink A. Kotlov A. Lushchik A. Lõhmus R. Lõhmus K. Mauring R. Rammula (2004) K. Õige (2004) U. Repinski (2004, 2005) D. Troskov (2004) V. Boltrushko (2004) A. Floren (2004), A. Kärkkänen (2004), I. Kärkkänen (2004), M. Kodu (2005) L. Aarik (2004, 2005), K. Isakar (2004, 2005) J. Shulga (2005) R. Sarakvasha (2005) S. Galayev (2005) M. Lobjakas (2004, 2005) U. Vesi (2004, 2005), M. Lobjakas (2004, 2005), S. Leinberg (2005), S. Vlassov (2005), M. Timusk (2005) S. Miller (2005) 202 • Biannual Report 2004/2005 V. Nagirnyi A. Niilisk E. Nõmmiste V. Palm V. Peet E. Realo K. Rebane V. Reedo K. Reivelt A. Rosental K. Saal P. Saari I. Sildos A. Suisalu A. Sherman A. Tarre T. Tätte S. Zazubovich E. Vasil’chenko R. Sarakvasha (2005) R. Pärna (2005) T. Hein (2004, 2005) M. Pärs (2004) S. Burak (2004, 2005) A. Uljas (2004, 2005), L. Aarik (2004, 2005), K. Isakar (2004, 2005) M. Pärs (2004) M. Järvekülg (2005) H. Valtna (2004, 2005) R. Pärn (2005) M. Plaado (2005) H. Valtna (2004, 2005), G. Savustyan (2005) S. Lange (2004), M. Pärs (2004), A. Lukner (2005) M. Kleemann (2004, 2005), U. Visk (2005) D. Bobkov (2004, 2005) R. Pärn (2005) M. Paalo (2005) A. Makhov (2005) S. Galayev (2005) 13. AWARDS 2004 The Estonian Science Prize for long and productive research and development – Ch. Lushchik The Estonian Science Prize in exact sciences – N. Kristoffel, Mechanism of MgB2 superconductivity The Prize of the Estonian Ministry of Education and Research for the students’ investigations published in 2004 – postgraduate students A. Krasnikov, H. Valtna The Science Prize of the Estonian Science Foundation for the postgraduate students (doctoral level) – V. Issakhanyan, V. Kiisk, A. Kotlov, A. Krasnikov The Students’ Scholarship of the Institute of Physics, UT – V. Issakhanyan, M. Kleeman, V. Krasnenko, S. Vlassov 2005 The Estonian Science Prize in technical sciences – A. Lõhmus, R. Lõhmus, Development of micro- and nanotechnological research methods for elaboration of industrial materials The Annual Prize of the Estonian Physical Society – J. Aarik, Advancement of atomic layer deposition method and investigation of this films prepared by this technique The Prize of the Estonian Ministry of Education and Research for the students’ investigations published in 2005 – postgraduate student A. Krasnikov The Students’ Prize of the Estonian Academy of Sciences – M. Moppel, Development of confocal microscope for Raman and luminescence measurements 204 • Biannual Report 2004/2005 The Best Poster Award of TNT2005 “Trends in Nanotechnology” (Ovideo) – M. Järvekülg The Best Poster Award of International Conference “Atomic and Molecular Pulsed Lasers” (Tomsk) – A. Lissovski The Students’ Scholarship of the Institute of Physics, UT – M. Järvekülg, M. Paalo, U. Visk, H. Valtna, S. Lange, R. Rammula. 14. ACKNOWLEDGEMENTS Institute of Physics and its laboratories would like to thank our colleagues from the following universities, institutions and organizations for fruitful scientific co-operation and/or financial support in 2004–2005: x x x x x x x x x x x x x x x x x x x x Australian Nuclear Science and Technology Organization (ANSTO), Materials Division, Dr. D.R.G. Mitchell Chemnitz University of Technology, Prof. M. Schreiber CNR-NATO Outreach Fellowship Crafoord Foundation Cornell University, Prof. A.J. Sievers Danish University of Technology, Prof. J. Bohr Deutsche Forschungsgemeinschaft Estla Ltd., J. Berik Estonian Science Foundation European Commission Hasselblad Foundation Lund University, MAX-Lab, Prof. N. Mårtensson Lund University, Department of Atomic Spectroscopy, Prof. I. Martinson NordForsk Trygger Foundation University of Hamburg, Prof. G. Zimmerer, Prof. W. Wurth University of Milan-Bicocca, Prof. G. Benedek University of Oulu, Prof. S. Aksela University of Uppsala, Ångström Laboratory, Dr. Jun Lu, Dr. M. Ottoson, Prof. A. Harsta University of Valladolid, Prof. S. Duena