Berlin 2012 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 34: Magnetization / Demagnetization Dynamics III

MA 34.8: Vortrag

Mittwoch, 28. März 2012, 17:00–17:15, H 1012

Gilbert damping parameter for transition metals and alloys at finite temperature: first-pinciples calculations — •S. Mankovsky, D. Koedderitzsch, and H. Ebert — Dept. Chemie/Phys. Chemie, Universität München, Butenandtstr. 11, D-81377 München, Germany

We present the results of calculations of the Gilbert damping parameter α for pure 3d transition metals as well as for disordered alloys containing magnetic 3d elements. The calculations of the α parameter were performed within the linear response formalism via the KKR Green’s function band structure method. The role of various influences on the Gilbert damping have been investigated: chemical composition, crystal lattice structure, spin-orbit coupling of the elements and temperature. In particular, we focus here on the finite temperature dependence of the Gilbert damping, caused by temperature induced structural and magnetic disorder in the system. These scattering mechanisms have been accounted for by means of the alloy analogy scheme using the coherent potential approximation (CPA) alloy theory. The effects of structural and magnetic disorder are accounted for separately as well as simultaneously, to see their interrelation in pure materials as well as in the presence of impurities. The theoretical results for the Gilbert damping parameters are compared with available experimental data.