Transport properties of doped permalloy via ab-initio calculations: effect of the host disorder.

The question to what extent the approaches useful for analyzing transport properties of doped crystals can be applied to doped alloys is explored via ab-initio calculation for permalloy doped with V, Co, Pt, and Au. For that purpose, the Kubo-Bastin equation is solved within the fully relativistic Korringa-Kohn-Rostoker Green function formalism. Finite temperature effects are treated by means of the alloy analogy model. We show that the fact that the host is disordered and not crystalline has a profound effect on how the conductivities characterizing the anomalous Hall effect and the spin Hall effect depend on the dopants concentration. Several relationships between quantities characterizing charge and spin transport are highlighted. Introducing the finite temperature changes the overall trends significantly. Our theoretical results compare well with available experiments.