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MA: Fachverband Magnetismus
MA 4: Magnetic Coupling Phenomena/ Exchange Bias
MA 4.6: Vortrag
Montag, 14. März 2011, 12:15–12:30, HSZ 403
Room-temperature magnetocurrent in antiferromagnetically coupled Fe/Si/Fe — •Maximilian Schmid1, Rashid Gareev1, Johann Vancea1, Christian H. Back1, Reinert Schreiber2, Daniel Bürgler2, Claus M. Schneider2, Frank Stromberg3, and Heiko Wende3 — 1Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany — 2Forschungszentrum Jülich, Institute of Solid State Research Electronic Properties, 52428 Jülich, Germany — 3Faculty of Physics and Center for Nanointegration Duisburg Essen (CeNIDE), University of Duisburg Essen, 47048 Duisburg, Germany
Epitaxial Si-based hybrid ferromagnet/semiconductor tunneling structures demonstrate very strong antiferromagnetic coupling (AFC) as well as unusual resonant-type megnetoresistance, which vanishes at temperatures above T≅50K. Magnetoresistance effects in Fe/Si/Fe close to room temperature (RT) were not established yet. Here, by using the ballistic electron magneto microscopy (BEMM) technique, with its nanometer-scaled locality, we managed to observe for the first time a spin-dependent ballistic magnetotransport in AFC structures. We found that the hot-electron collector current with energies above the Fe/GaAsP Schottky barrier reflects the relative orientations of the electrodes and changes from IcAP≅50 fA for antiparallel alignment to IcAP≅150 fA for the parallel one. Thus, the magnetocurrent([(IcP−IcAP)/(IcAP)]) is near 200% at RT. The measured BEMM hysteresis loops match nicely with the magnetic MOKE hysteresis data. This work is supported by the project DFG 9209379.