Influence of Fe Impurity on Spin Hall Effect in Au

We investigated the influence of Fe impurity on spin Hall effect in Au using multi-terminal devices consisting of an FePt perpendicular spin polarizer and a Au Hall cross with different Fe impurity concentrations. As the Fe impurity concentration was increased in the range of 0-0.95 at.%, the resistivity of Au doped with Fe increased and the spin diffusion length decreased from 35 nm to 27 nm. On the other hand, the spin Hall angle for Au doped with Fe, evaluated from the spin injector-Hall cross distance dependence of spin Hall signals, was approximately 0.07, independent of the Fe concentration. The experimental results provide important information for understanding the mechanism of the large spin Hall effect.