Regensburg 2002 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

MA: Magnetismus

MA 6: Spinabhängige Transportphänomene I

MA 6.6: Vortrag

Montag, 11. März 2002, 16:30–16:45, H22

Ab initio calculations of the magnetoresistance and exchange constants of ferromagnet-semiconductor multilayers — •Alexander Perlov, Voicu Popescu, and Hubert Ebert — Physik. Chemie, Universität München, Butenandtstr. 5-13, 81377 München

The deposition of magnetic materials on semiconductors allowed the synthesis of a number of new artificial materials with potential applications in magneto-electronics. In particular ferromagnetic- semiconductor (FM/SC) heterostructures have a potential use in devices based on the TMR (tunneling magneto-resistance). We report results of calculations of the electronic, magnetic, transport and magneto-optical properties of Fe/GaAs and Fe/Ge multilayer systems that are meant to model FM/SC/FM trilayer systems.

On the base of the generalized Bloch theorem we have calculated the electronic structure of a set of spin-spiral structures, which allows us to extract averaged interlayer exchange parameters and their dependence on the width of the semiconductor spacer. Also the dependence of the dc conductivity and magneto-resistance on the width of the semiconductor layer and the relative angle between layers magnetic moments is presented and discussed. These are calculated on the basis of the Drude model for ballistic and diffusive regimes.