Scaling behavior of the spin pumping effect in ferromagnet/platinum bilayers

TL;DR

This study systematically investigates the spin pumping effect in various ferromagnet/platinum bilayers, revealing universal scaling behavior and consistent polarity of the inverse spin Hall voltage across diverse magnetic materials.

Contribution

It provides comprehensive experimental evidence supporting the universal scaling law of spin pumping and inverse spin Hall effect in different ferromagnetic materials.

Findings

V_ISH has the same polarity across all samples

V_ISH scales with the magnetization precession cone angle

Results support current theoretical models of spin pumping

Abstract

We systematically measured the DC voltage V_ISH induced by spin pumping together with the inverse spin Hall effect in ferromagnet/platinum bilayer films. In all our samples, comprising ferromagnetic 3d transition metals, Heusler compounds, ferrite spinel oxides, and magnetic semiconductors, V_ISH invariably has the same polarity. V_ISH furthermore scales with the magnetization precession cone angle with a universal prefactor, irrespective of the magnetic properties, the charge carrier transport mechanism or type. These findings quantitatively corroborate the present theoretical understanding of spin pumping in combination with the inverse spin Hall effect.