Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 17: Magnetic Thin Films I

MA 17.6: Vortrag

Mittwoch, 25. März 2009, 11:30–11:45, HSZ 04

Properties of the Fe/GaAs(110) interface investigated by ab inito calculations — •Anna Grünebohm, Heike C. Herper, and Peter Entel — Fachbereich Physik, Universität Duisburg-Essen, Duisburg

Fe/GaAs is a widely used system for spintronic devices. For example the small lattice mismatch (<2%) and the cheap preparation of layered systems are promising. Because of this many studies on Fe/GaAs have been performed in the last decades mostly on the (001) direction. Recently the (110) direction has attracted plenty of attention as the free GaAs(110) surface doesn't reconstruct and allows to grow flat interfaces. Unfortunately, diffusion and alloy formation occur at both interfaces which may lead to reduced spin injection and magnetic inactive regions.

To get an insight into the interface properties we do calculations within the PAW method using VASP [1] adopting the GGA/PBE form for the exchange-correlation potential. To simulate the free surface the slap method is used thereby one side of the slab is passivated through pseudo-hydrogen to guarantee a bulk-like behavior in a moderate sized slap. The adsorption of single Fe-atoms as well as the first monolayers of iron are investigated with respect to the energy landscape for different structures and the magnetic moments. While diffusion of atoms through the interface was shown to be low in energy no magnetic inactive phase could be observed. Hence our results don't show any fundamental limitations for spintronic applications.

[1] G.Kresse and J.Furthmüller, Phys. Rev. B 54, 11169 (1996)