Dresden 2006 – wissenschaftliches Programm

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MA: Magnetismus

MA 6: Invited Talks Vandersypen / Herper

MA 6.2: Hauptvortrag

Montag, 27. März 2006, 14:15–14:45, HSZ 03

Electronic transport in ferromagnetic films and wires: An ab initio study — •Heike Herper — Theoretische Tieftemperaturphysik, Universiät Duisburg-Essen, Campus Duisburg, 47048 Duisburg, Germany

Domain walls can be viewed as special type of interfaces. In case of relatively thin domain walls a magnetoresistance effect can be expected due to the domain wall, which has been addressed in a considerable number of experimental and theoretical studies. However, only a few ab initio investigations have been done in this field. We have determined the influence of domain walls on the resistance of ferromagnetic Co and Ni layers employing the fully-relativistic, spin-polarized Screened Korringa-Kohn-Rostoker method (SKKR) and the Kubo-Greenwood formula. In order to investigate the magnetoresistance in systems with reduced dimensions like thin wires we have used a real-space SKKR and Kubo-Greenwood method. The magnetoresistance and the formation energy of the domain walls have been calculated depending on the thickness and the type of the domain wall. As expected, the formation energy decreases with increasing number of FM layers. Throughout the calculations all domain walls are assumed to be oriented parallel to the planes of the layers. To avoid contributions from the anisotropic magnetoresistance, the current is assumed to flow perpendicular to the domain walls, i.e. parallel to the surface normal. The domain wall resistance shows the same width dependence as predicted by Zhang and Levy.
This work is supported by the SFB 491.