Unified First-Principles Study of Gilbert Damping, Spin-Flip Diffusion, and Resistivity in Transition Metal Alloys

Abstract

Using a formulation of first-principles scattering theory that includes disorder and spin-orbit coupling on an equal footing, we calculate the resistivity ρ, spin-flip diffusion length l(sf), and Gilbert damping parameter α for Ni(1-x)Fe(x) substitutional alloys as a function of x. For the technologically important Ni(80)Fe(20) alloy, Permalloy, we calculate values of ρ = 3.5 ± 0.15 μΩ cm, l(sf) = 5.5 ± 0.3 nm, and α = 0.0046 ± 0.0001 compared to experimental low-temperature values in the range 4.2-4.8 μΩ cm for ρ, 5.0-6.0 nm for l(sf), and 0.004-0.013 for α, indicating that the theoretical formalism captures the most important contributions to these parameters.