Unified first-principles study of gilbert damping, spin-flip diffusion, and resistivity 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 𝜌, spin-flip diffusion length 𝑙sf, and Gilbert damping parameter 𝛼 for Ni1−𝑥⁢Fe𝑥 substitutional alloys as a function of 𝑥. For the technologically important Ni80⁢Fe20 alloy, Permalloy, we calculate values of 𝜌 =3.5 ±0.15  𝜇⁢𝛺 cm, 𝑙sf =5.5 ±0.3  nm, and 𝛼 =0.0046 ±0.0001 compared to experimental low-temperature values in the range 4.2–4.8  𝜇⁢𝛺 cm for 𝜌, 5.0–6.0 nm for 𝑙sf, and 0.004–0.013 for 𝛼, indicating that the theoretical formalism captures the most important contributions to these parameters.