Download Curriculum vitae

Curriculum vitae
Name:
Mahrous R. Ahmed
Permanent Address:
Physics Department, Science Faculty, Sohag
University, 82524, Sohag, Egypt.
Phone:
(2) 093 461 2927 –
Fax:
(2) 093 460 1159
Permanent e-mail:
[email protected]
Date of birth:
January 03, 1970 Sohag (Egypt)
Nationality:
Egyptian
Marital status:
Married
Education:
Feb 20013: Assistant Prof. degree in Theoretical and Experimental Solid State Physics.
Sept 2006:
PhD degree in Theoretical Condensed Matter Physics : The Theory of the
Relaxation Phenomena in Manganites, Supervisor : prof. G. A. Gehring,
Department of Physics and Astronomy, University of Sheffield, Sheffield, S3
7RH, UK.
Aug 2003:
Master of philosophy (MPhil) degree in Theoretical Condensed Matter
Physics : Spin Frank-Condon Effect, Supervisor : prof. G. A. Gehring, Department
of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, UK.
June 1998:
Master degree in Condensed Matter Physics : Transport properties of the
Ga0.45In0.55Sb Alloy, Supervisor : prof. Dr. M. M. Ibrahim Physics
Department, Science Faculty, Sohag, Egypt.
Oct 1995:
Master diploma in Condensed Matter Physics : Theoretical Solid State Physics,
Statistical Physics, Surface Physics, Crystal Structure, Defects in
Solids, and Mathematical Physics)
June 1992:
B.SC. with Excellent in Physics.
Physics Department, Sohag Science Faculty, Assiut University, Egypt.
June 1988:
High School, Mathematics and Physics.
Al-Askaria Secondary School, Sohag (Egypt).
Experience:
2009/…………: Teaching Lectures in General Physics (Phys 1) and (Phys 2), Quantum Mechanics,
Modern Physics, Classical mechanics, Theory of Electromagnetism, Applied
Electronics, Solid state Physics, for the university College student, Umm-Elqura
University Makkah, KSA.
2007/2009: Teaching lectures in Physics for 3rd and 4th levels: Statistical Physics,
Electrodynamics, Theory of Electromagnetism, Physical Electronics, Physical
optics and Electricity and Magnetism.
1993/2002: Teaching Tutorials in Physics: Practical Works in condensed matter Physics
Solid
state
physics,
Electromagnetic,
Optics,
Electricity,
Oscillators,
Semiconductors 2nd, 3rd and 4th levels for Physics and Mathematics, and
Chemistry
Department students in Science Faculty)
1993/2002: Teaching Practical Works in Physics: Solid state physics, Electromagnetic,
Optics, Electricity, Oscillators, Semiconductors (1th, 2nd, 3rd and 4th year
Educational faculty.
Occupation:
September-… 2009
Lecturer in Physics Department, Uneversity College, Um-Elqura
University, Makkah, KSA.
April-May 2009:
Academic visitor in Department of Physics, University of Salford, Salford,
Great Manchester, UK.
June-August 2008:
Academic visitor in Department of Physics and Astronomy, University of
Sheffield, Sheffield, UK.
Jan 2007/...:
Lecturer in Physics Department, Sohag Science Faculty, Sohag University,
Egypt.
2002/2006:
Assistant Researcher in Department of Physics and Astronomy,
University of Sheffield, Sheffield, UK.
1998/2002:
Assistant Lecturer in Physics Department, Sohag Science Faculty, South
Valley University, Egypt.
1993/1998:
Demonstrator in Physics Department, Sohag Science Faculty, Assiut Uni-
versity, Egypt.
statement of research interests :
-
Study the magneto caloric effect in the magnetic material experimentally and
theoretically to enhance the magnetic properties in order to get new magnetic
refrigerators materials.
-
Obtaining the critical exponents for the thermal physical quantities using the Monte
carlo simulation for the Ising model.
Theory of magnetism with temporal disorder applied to magnetically doped ZnO:
Insulating ZnO is magnetic when doped with transition metals but this magnetization decreases
rapidly as the carriers become mobile1. The magnetic interaction is mediated by occupied
polaron orbits because the electron orbits associated with defects are exchange coupled to
several magnetic ions. In the variable hopping regime the conductivity varies is controlled by
the parameter T0 that characterizes the probability of the carriers can hop between localized
states. When a carrier moves out of a localised orbit the exchange interactions between the
transition metal ions are changed suddenly. This time dependence of the exchange interactions
destroys the ferromagnetism.
We simulate an Ising model with ferromagnetic bonds J and antiferromagnetic bonds - J with
probability 1-q and q respectively. This is ferromagnetic for qqc. We change the arrangement
of the AF bonds after n Monte Carlo steps but keeping the same value of q. This random flipping
of the exchange interactions differs from the Glauber model in which the Ising model is
subjected to a random external field. The spin glass phase is characterised by long relaxation
times however the relaxation become slow even in the ferromagnetic phase as q increases. The
ferromagnetism is destabilised by the time dependent exchange even though the average
exchange =J(1-2q) is still positive. The phase diagram is calculated as a function of q and n.
The Theory of the Relaxation Phenomena in Manganites as a PhD degree with Prof.
Gillian.
1. A study is made of an anisotropic Potts model in three dimensions where the coupling
depends on both the Potts state on each site but also the direction of the bond between
them using both analytical and numerical methods. The phase diagram is mapped out for
all values of the exchange interactions. Six distinct phases are identified. Monte Carlo
simulations have been used to obtain the order parameter and the values for the energy
and entropy in the ground state and also the transition temperatures. Our Monte Carlo
calculations have been carried out on 3d finite cubic lattices (with linear size L = 8) with
periodic boundary conditions. All our simulations have made use of the Metropolis
algorithm with the spin being chosen at random, and with averaging performed over 105
Monte Carlo steps per site. In most of the phase diagram this gave clear results. Where
convergence was slow we checked that we had found the true ground state by both
increasing the number of Monte Carlo steps and also by looking at a L = 10 lattice as
explained below. Results at low temperatures were obtained by cooling down from a
hightemperature random configuration. Excellent agreement is found between the
simulated and analytic results. We find one region where there are two phase transitions
with the lines meeting in a triple point. The orbital ordering that occurs in LaMnO3 occurs
as one of the ordered phases.
2. A modified Potts model based on the physics of the manganese-oxygen bonds and two
different exchange interaction types, J1 and J2 , were proposed. The orbital ordering in
LaMnO3 is obtained when J1 is AF and J2 is FM. Local short range order is obtained above
Jahn-Teller temperature, TJT , and it reduced the entropy from kBloge3 to ssro ∼ (0.50.02)
and this value is well comparable to the experimental value obtained by Sanchez. When
J1 is AF and J2 is zero a line phase which represents orbital ordering disorder in LaMnO 3
above TJT is obtained . This line phase has no transition and its entropy is higher than ssro.
Transport properties of the Ga0.45In0.55Sb Alloy, as a Master degree with prof. M. Ibrahim,
prof. Mostafa M. Abd El-Rahim and prof. A. M. Aly . We have studied the transport properties of
the composition Ga0.45In0.55Sb in terms of studying the conduction behaviour, the
thermoelectric power (S), the Hall coefficient (RH), the charge carrier mobility (µ), the charge
carrier concentration (n) and the magneto-resistance coefficient (RM). On the other hand, the
structural properties are characterised by means of the XRD analysis, DTA and scanning
electron microscopy.It is propositioning that most of the transport properties are investigated
in a wide range of temperature 173 ≤ T ≤ 400K, applied magnetic field 0.0607 ≤ B ≤ 0.765 Tesla
and annealing was carried out isochronically in the range 50 ≤ Tan ≤ 400oC.
Research skills:
I have good knowledge of writing Fortran programs, simulating realistic systems using
Monte Carlo and statistical models such as Ising models and Potts models, fitting experimental
data, solving some quantum problems.
Computer skills:
I have a good knowledge of UNIX/LINUX, WINDOWS and MS-DOS operating systems. I have
been programming using FORTRAN language. I use LaTeX as well as Word in writing my
manuscripts.
Languages:
English, Arabic (mother tongue).
Publications:
[1] The phase Diagram for an anisotropic Potts model, M. R. Ahmed and G. A. Gehring, J. Phys. A:
Math. Gen. 38, 4047 (2005).
[2] Potts model for distortion transition in LaMnO3, Mahrous R. Ahmed and G. A. Gehring, Phys.
Rev. B 74, 014420 (2006).
[3] Magneto-optical study of the Verwey transition in magnetite, J. R. Neal, A. J. Behan, A.
Mokhtari, M. R. Ahmed, H. J. Blythe, A. M. Fox, G. A. Gehring, J. Mag. Mag. Mater. 310, (2007)
246.
[4] The spin Frank-Condon Effect, Mahrous R. Ahmed and G. A. Gehring, J. Phys.: Condens.
Matter 19, 256208 (2007).
[5] Transport Properties of Ga0.45In0.55Sb, M. M. Abd El-Raheem, M. M. Ibrahiem, A. M. Ahmed
and M. R. Ahmed, Egypt. J. Solids 30, 31-46 (2007).
[6] Investigation of zirconium oxynitride thin films deposited by reactive pulsed magnetron
sputtering, S H Mohamed, A M Abd El-Rahman and Mahrous R. Ahmed, J. Phys. D: Appl. Phys.
40, 7057(2007).
[7] Theory of magnetism with temporal disorder applied to magnetically doped ZnO, G A
Gehring, Mahrous R Ahmed, A J Crombie, J. App. Phys. 105, 1-3(2009).
[8] The volume collapse in LaMnO3 modelled using an anisotropic Potts model, Mahrous R
Ahmed and G A Gehring, Phys. Rev B. 79, 174106 (2009).
[9] Nitrocarburizing of AISI-304 stainless steel using high-voltage plasma immersion ion
implantation, A.M. Abd El-Rahman, S.H. Mohamed, M R. Ahmed, E. Richter, F. Prokert,
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with
Materials and Atoms 267, 10, 1792-1796 (2009).
[10]
Landau theory of compressible magnets near a quantum critical point, Gillian A.
Gehring1, and Mahrous R. Ahmed, JOURNAL OF APPLIED PHYSICS 107, 09E125 2010
[11]
Correlation of Magnetoresistance and Thermoelectric Power in La1-xLixMnOy Compounds,
Ahmed Mohamed Ahmed, Mahrous R Ahmed, Abed El Rahman Ahmed Saad, Journal of
Electromagnetic Analysis and Applications, 2011, 27-2.
References:
1. Prof. G A Gehring
Department of Physics and Astronomy,
University of Sheffield
Sheffield, S3 7RH, UK.
Fax (44) 0114 22 23555
E-mail: [email protected]
2. Prof. Peter Littlewood ,
Head of the Department of Physics,
The Cavendish Laboratory,
University of cambridge, 19, J J
Thomson Avenue Cambridge, CB3
HE, UK.
Tel: +44 (0)1223 337254
Fax: +44 (0)1223 337356
E-mail:[email protected]
3. Prof. D M Whittaker
Department of Physics and Astronomy,
University of Sheffield
Sheffield, S3 7RH, UK.
Fax (44) 0114 22 23555
E-mail: [email protected]
4. Prof. Ahmed M. Aly Physics Department,
Faculty of sciences
Sohag University,
82524, Sohag, Egypt.
Tel : + 20 93 4602 965
fax : + 20 93 4601 950
E-mail: fikry−[email protected]