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O: Fachverband Oberflächenphysik
O 52: Nanostructures at Surfaces: Dots, Particles, Clusters
O 52.13: Poster
Tuesday, March 21, 2017, 18:30–20:30, P1C
Selective nucleation of MnSb Islands on GaAs Substrates — •Christian Klump1, Bo Zhang1, Julian Ritzmann2, Arne Ludwig2, Andreas Wieck2, and Ulrich Köhler1 — 1Experimentalphysik IV, AG Oberflächen, Ruhr-Universität Bochum, Germany — 2Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Germany
For future spintronic semiconductor devices, spin polarization and injection is one important prerequisite. Ferromagnetic or half-metallic materials can be used as efficient spin-injectors. As with the underlying semiconductor quantum dots, it is necessary to be able to grow the spin-injector material site-selectively. Prestructuring the substrate and strain-driven nucleation are two approaches for site-selective growth.
Prestructuring the substrates introduces defects to the surface and may deteriorate the quality of subsequent island growth. Examples of growth on a prestructured substrate are shown.
Strain-driven nucleation, on the other hand, opens the prospect of pin-pointing exactly one spin-injector island to one semiconductor QD by using the inherent strain induced by the underlying semiconductor QD, so spin-injection can be studied for each QD, individually.
MnSb is an interesting material for spin-injection with its high Curie temperature of 587 K and its compatibility with semiconductor substrates. The strain induced pairing of MnSb islands with InAs QDs is studied. MnSb islands were grown on different GaAs substrates by MBE. Structural and magnetic properties have been studied by STM, LEED and MOKE.