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arXiv · 1102.4551

Ab-initio calculation of the Gilbert damping parameter via linear response formalism

H. Ebert·S. Mankovsky·D. Koedderitzsch·P. J. Kelly
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Abstract

A Kubo-Greenwood-like equation for the Gilbert damping parameter $α$ is presented that is based on the linear response formalism. Its implementation using the fully relativistic Korringa-Kohn-Rostoker (KKR) band structure method in combination with Coherent Potential Approximation (CPA) alloy theory allows it to be applied to a wide range of situations. This is demonstrated with results obtained for the bcc alloy system Fe$_x$Co$_{1-x}$ as well as for a series of alloys of permalloy with 5d transition metals. To account for the thermal displacements of atoms as a scattering mechanism, an alloy-analogy model is introduced. The corresponding calculations for Ni correctly describe the rapid change of $α$ when small amounts of substitutional Cu are introduced.

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H. Ebert, S. Mankovsky, D. Koedderitzsch, P. J. Kelly. 2011-02-22. Ab-initio calculation of the Gilbert damping parameter via linear response formalism. https://doi.org/10.1103/physrevlett.107.066603

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