Dresden 2011 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 85: Poster Session II
HL 85.37: Poster
Thursday, March 17, 2011, 18:00–21:00, P4
Transport properties of ferromagnet-semiconductor hybrids — •Lakshmy Ravindran1, Rasmus Ballmer1, Sven Buchholz1, Saskia F. Fischer2, Ulrich Kunze1, Arne Ludwig3, Dirk Reuter3, and Andreas Wieck3 — 1Werkstoffe und Nanoelektronik, Ruhr-Universität Bochum, D-44780 Bochum, Germany — 2Neue Materialien, Humboldt Universität zu Berlin, D-12489 Berlin, Germany — 3Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum, Germany
Ferromagnet-semiconductor hybrid devices integrate nanoscale magnets with semiconductor nanostructures leading to magnetoelectronic devices with high storage density and reduced energy dissipation. In a ferromagnet-semiconductor hybrid device the resistivity of the semiconductor could be controlled by the ferromagnetic element [1]. Our devices consist of GaAS/AlGaAs heterostructure field effect transistor(HFET) with a ferromagnetic Permalloy(Py) nanogate only 35 nm apart from the GaAs channel. The nanostructuring is done with electron beam lithography and the GaAs channel is patterned by shallow wet etching. The 20 nm thick Py gate is fabricated by electron beam lithography, metal evaporation and lift-off process. The angle-dependent magnetoresistance measurements in external low magnetic fields of the order of 150 mT are done with lock-in technology. The measurements infer a positive magnetoresistance for an external magnetic field applied in the longitudinal direction which is due to the magnetic fringing fields emanating from the Py gate.
[1] J.P.Bird, et al., IEEE Trans, Magn, 44, 4707(2008)