First-Principles Theory of Spontaneous-Resistance Anisotropy and Spontaneous Hall Effect in Disordered Ferromagnetic Alloys

A fully relativistic first-principles theory of the conductivity of disordered magnetic alloys based on the Kubo-Greenwood formalism and the spin-polarised relativistic Korringa-Kohn-Rostoker coherent-potential approximation (SPRKKR-CPA) method is presented. This new approach allows for a treatment of spin-orbit coupling and spin polarisation on an equal footing and to account properly for the reduction in symmetry caused by the simultanous presence of them that way. Consequently–in contrast to previous approaches–one has access to a parameter-free theoretical description of the spontaneous-resistance anisotropy and the spontaneous Hall resistivity of magnetic alloys. A first application to the system Fe-Ni yields results which are in very satisfying agreement with experiment.