Berlin 2008 – scientific programme
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MA: Fachverband Magnetismus
MA 15: Magnetic Thin Films I
MA 15.4: Talk
Tuesday, February 26, 2008, 11:15–11:30, H 1012
Effects of interdiffusion at Fe/GaAs interfaces — •Ellen Schuster1, Werner Keune1, Heiko Wende1, Ahmed Naitabdi2, and Beatriz Roldan Cuenya2 — 1Universität Duisburg-Essen, Germany — 2University of Central Florida, Orlando, USA
Fe/GaAs is an interesting candidate among ferromagnet/semiconductor heterostructures for realization of spintronic devices in particular for the injection of a spinpolarized current. For this purpose a well ordered structure and prevention of dead magnetic layers at the interface are essential. The presented investigations adress the interdiffusion at the interface of room-temperature grown Fe(001) layers on top of Ga terminated GaAs(001)-(4x6) surfaces. X-Ray photoelctron spectroscopy (XPS) measurements of up to 4 monolayers (ML) thick Fe layers prove the segregation of Ga atoms to the Fe surface. Further, structural and magnetic properties are inferred from 57Fe conversion electron Mössbauer spectroscopy (CEMS) at 5 nm thick Fe layers. For this purpose, different samples are deposited with Mössbauer active 2 ML thick 57Fe tracer layers at different distances from the interface. With this technique the effect of interdiffusion at the Fe/GaAs interface can be detected up to a distance of 14 ML within the Fe layer. RHEED measurements during initial Fe growth by MBE show a non-monotonic behaviour of the in-plane lattice parameter. This result is in agreement with CEMS. Supported by DFG (SFB491).