Thin film physics

A huge research topic was found due to the discovery of the uniaxial anisotropy in a magnetic, coupled ferromagnet/antiferromagnet bilayer system in 1956. Especially the GMR effect discovered by the Nobel laureate Grünberg and Fert in the 1980s stimulated the research on the so called Exchange Bias effect which causes a shift of the hysteresis and, therefore, a predominant direction of the magnetization of the ferromagnetical moments. However, despite intensive research the Exchange Bias theory is still not understood fundamentally. But there is much potential for different applications which are nowadays adopted i.e. at the sensory devices on hard disks.

In the experimental physics work group IV the Exchange Bias effect of a layer system can be tuned locally in direction and strength by bombardment with helium ions. Therewith arbitrary artificial domain structures with defined stray fields can be created and observed by magnetic and structural methods (i.e. AFM/MFM). The aims are to adjust an exchange biased layer system to special applications due to well-defined production and bombardment parameters and to expand the application research with special setups for the different experiments which are based in research fields like particle transport, biosensors and well-defined structuring of magnetic fields.