Berlin 2008 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 32: Postersession II: Spinstruct./Phase Trans. (1-10); Spinelectronics (11-15); Thin Films (16 - 36); Particles/Clusters (37-45); Multiferroics (46-54); Spindynamics/Spin Torque (55 - 76); Post Deadlines (77-79)

MA 32.71: Poster

Freitag, 29. Februar 2008, 11:15–14:00, Poster E

Spin diffusion in metals: ab initio treatment of impurity scattering — •Peter Zahn, Martin Gradhand, Dmitry Fedorov, and Ingrid Mertig — Dept. of Physics, Martin Luther University Halle-Wittenberg, D-06099 Halle, Germany

One of the main issues of spintronics is the spin relaxation, which determines the spatial extension of spin accumulation in Spin Hall experiments, and the spin diffusion length in spin injection experiments. We consider the Elliott-Yafet mechanism caused by the scattering at point defects. The electronic structure of the metallic host and the perturbation of the potential in the vicinity of the defects is calculated in the framework of density-functional theory using a multiple scattering Green’s function Korringa-Kohn-Rostoker scheme. The spin-orbit coupling is treated as a perturbation in first order of the Born series expansion of the transition matrix. In the first implementation of the formalism its action is restricted to the impurity site. Our calculations give the momentum and spin relaxation time of conduction electrons in Cu containing different types of impurities in good agreement with residual resistivity measurements and CESR results. The situation is less satisfying for the case of Al and Mg hosts with defects of comparable core charge. In these cases a relativistic treatment is necessary to obtain the so-called spin hot spots on the Fermi surface correctly. These states with a strong spin-mixed character cause a strong spin relaxation due to the chemical potential scattering by the defects. First results are discussed.