Self-consistent determination of spin Hall angles in selected5dmetals by thermal spin injection

Abstract

We demonstrate a self-consistent and versatile method to determine the relative spin Hall angle ${\ensuremath{\theta}}_{\text{SH}}$ and spin diffusion length ${\ensuremath{\lambda}}_{\text{SF}}$ of selected $5d$ metals (Pt, Au, Ta, and W) by thermal spin injection from a common ferromagnetic insulator, yttrium iron garnet, into thin metal films of various thicknesses. The values of ${\ensuremath{\theta}}_{\text{SH}}$ for Pt and Au are opposite in sign to those of Ta and W. The inverse spin Hall effect voltage depends on spin Hall resistivity, which is the product of ${\ensuremath{\theta}}_{\text{SH}}$ and electrical resistivity. We also show evidence of magnetic proximity effects including magnetoresistance and the anomalous Hall effect in these $5d$ metals, except for Au.