Berlin 2008 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 55: Poster Session III - MA 141/144 (Methods: Atomic and Electronic Structure; Particles and Clusters; Heterogeneous Catalysis; Semiconductor Substrates: Epitaxy and Growth+Adsorption+Clean Surfaces+Solid-Liquid Interfaces; Oxides and Insulators: Solid-Liquid Interfaces+Epitaxy and Growth; Phase Transitions; Metal Substrates: Adsorption of Inorganic Molecules+Epitaxy and Growth; Surface Chemical Reactions; Bimetallic Nanosystems: Tuning Physical and Chemical Properties; Oxides and insulators: Adsorption; Organic, polymeric, biomolecular films; etc.)
O 55.25: Poster
Mittwoch, 27. Februar 2008, 18:30–19:30, Poster F
Magnetic and structural investigations of thin iron layers on GaAs(001) and GaAs(110) surfaces with and without an MgO intermediate layer — •Carsten Godde1, Sani Noor1, Christian Urban1, Igor Barsukov2, Jürgen Lindner2, and Ulrich Köhler1 — 1Institut für Experimentalphysik IV/ AG Oberflächen, Ruhr-Universität Bochum, Germany — 2Institut für Experimentalphysik / Festkörperphysik, Universität Duisburg / Essen, Germany
The structure and the magnetic behaviour of Fe-layers on GaAs(001) and GaAs(110) were studied in a UHV system that offers the means for structural analysis by STM and LEED and magnetic characterization by MOKE during deposition. The preparation of the GaAs(001) and GaAs(110) polished wafer surfaces consisted of cycles of sputtering and annealing, in the case of the cleaved GaAs(110) surface no in situ preparation was necessary. On all samples the structure of the Fe-layer when grown at 20°C is strongly influenced by the substrate morphology. At elevated growth temperature a disrupted Fe-layer develops. Using MgO as an intermediate layer the structural quality is substantially reduced. The uniaxial anisotropy of Fe on GaAs(110) surfaces is profoundly influenced by the MgO intermediate layer. The effect of annealing up to 500°C on the structure and the magnetic behaviour were studied. Although smooth layers with large islands develop, STM shows that Ga and As from the substrate diffuse to the Fe-island top. On GaAs(001) the substrate reconstruction changes from an initially present (2x6) to a As-rich (2x4).