Ab-initio study of the resistivity, Gilbert damping and spin-flip diffusion in transition metal alloys

Using a formulation of first-principles scattering theory that includes disorder and spin-orbit coupling on an equal footing, we calculate the resistivity $\rho $, spin-flip diffusion length $\lambda _{sf}$ and the Gilbert damping parameter $\alpha $ for Fe$_{x}$Ni$_{1-x}$ substitutional alloys as a function of x over the entire concentration range. For the technologically very important Fe$_{20}$Ni$_{80}$ alloy, permalloy, we calculate values of $\rho $ = 3.7$\pm $0.5 Ohm-cm, $\lambda _{sf}$ = 5.2$\pm $0.2 nm and $\alpha $ = 0.0046$\pm $0.002 compared to experimental low-temperature values in the range 4.4-5.1 Ohm-cm for $\rho $, 5.0-6.0 nm for $\lambda _{sf}$ and 0.005-0.009 for $\alpha $ indicating that our scattering theoretical formulation captures the most important contributions to these parameters. Work carried out with A.A. Starikov in collaboration with A. Brataas, Y. Tserkovnyak and G.E.W. Bauer.