Dresden 2014 – scientific programme

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O: Fachverband Oberflächenphysik

O 17: Semiconductor Substrates

O 17.10: Talk

Monday, March 31, 2014, 18:15–18:30, PHY C 213

A photoelectron diffraction study of the Fe/GaAs(4x2)-interface — •Dominique Handschak, Frank Schönbohm, Tobias Lühr, Christoph Keutner, Ulf Berges, and Carsten Westphal — Exp. Physik 1/DELTA, TU Dortmund, Otto-Hahn-Str. 4, 44221 Dortmund

In this study we investigate a system of a (4x2)-reconstructed GaAs(001) substrate with an Fe adsorbate. This system is applied in the field of spintronics, which use the GMR (giant magneto resistance) effect. Especially the interface between this two layers has a strong influence on the efficiency of the effect. The method of x-ray photoelectron diffraction (XPD) is an excellent tool for investigating this system, because it is chemical and interface sensitive. The angle-resolved measurement yield structural information due to scattering and diffraction effects of the photoelectron. The GaAs substrate is found in the well ordered (4x2)-reconstructed structure. XPD pattern of Ga 3d and As 3d reveal that the reconstruction is not lifted due to the Fe deposition. The Fe/GaAs interface is formed by a pyramid-like structure of the iron layers. The strongest lateral shift is found in the first Fe-monolayer with regard to the GaAs substrate and decreases evenly to zero with every additional monolayer towards the surface. Thereby the topmost layers are well bcc-ordered with the Fe-lattice constant of a(Fe) = 2.866Å.