Spin diffusion length of Permalloy using spin absorption in lateral spin valves

TL;DR

This study measures the spin diffusion length of Permalloy using spin absorption in lateral spin valves, revealing a linear relationship with conductivity and confirming Elliott-Yafet as the dominant relaxation mechanism.

Contribution

The paper provides a detailed temperature-dependent analysis of Permalloy's spin diffusion length and establishes a universal relation with resistivity, supported by literature data.

Findings

Spin diffusion length of Permalloy is inversely proportional to resistivity.

Elliott-Yafet mechanism dominates spin relaxation in Permalloy.

Established a universal relation: λ_Py ≈ 0.91 / ρ_Py.

Abstract

We employ the spin absorption technique in lateral spin valves to extract the spin diffusion length of Permalloy (Py) as a function of temperature and resistivity. A linear dependence of the spin diffusion length with conductivity of Py is observed, evidencing that Elliott-Yafet is the dominant spin relaxation mechanism in Permalloy. Completing the data set with additional data found in literature, we obtain $\lambda_{Py}= (0.91\pm 0.04) (f\Omega m^2)/\rho_{Py}$.