Download Metallic thin films possess unique magnetic properties, which is

04652
Exchanged-Biased Magnetic Films
May Liang
Mentor: Herbert Hopster
Metallic thin films possess unique magnetic properties, which is absent in their bulkier form.
Through studying the hysteresis curves, which records the change of the magnetization of the sample
with a changing external magnetic field, it is observed that the samples have different values of
magnetization. These values depend on the change of the external magnetic field, and reach extreme
values at the saturation points. The focus of this project is exchanged-biased magnetic films. When
ferromagnetic ultra-thin films on the nano-scale are in contact with antiferromagnetic film, the
properties of the ferromagnet can be greatly altered due to magnetic interface coupling. Exchange
bias means that the antiferromagnetic film imposes a preferred magnetization direction on the
ferromagnet. In this project we deposit ultra-thin (thickness on the order of 10 nm) films of different
materials to produce exchange-coulpled bi-layers of Fe and Mn. The sample preparation is done
under ultra-high vacuum (UHV) conditions in the 10-10 Torr range. Materials are evaporated from
high-purity electron beam evaporation sources. The magnetic properties are investigated ex-situ by
magneto-optical Kerr effect (MOKE) measurements. Temperature dependent hysteresis curves look
for a difference in the hysteresis curve of the ferromagnetic layer (Fe) due to the magnetic ordering
of the antiferromagnetic (Mn) layer.