Disentanglement of bulk and interfacial spin Hall effect in ferromagnet/normal metal interface

作者:Zhou, X.; Tang, M.; Fan, X. L.; Qiu, X. P.*; Zhou, S. M.*
来源:Physical Review B, 2016, 94(14): 144427.
DOI:10.1103/PhysRevB.94.144427

摘要

Spin Hall effect in PdPt alloys in contact with ferromagnetic Ni80Fe20 alloys has been studied by spin torque ferromagnetic resonance technique. The spin torque spin Hall angle (ST-SHA) proves to be contributed by the interfacial and bulk SHAs. The bulk SHA is dominated by the skew scattering and reaches a maximal value for the largest randomization of Pt and Pd atoms at the intermediate alloy composition. In particular, the interfacial SHA becomes prominent for Pt-rich alloys. This phenomenon indicates the enhanced Rashba spin-orbit coupling at the interface, as Pt has a stronger spin-orbit coupling and larger z-potential gradient compared to Pd. The present work highlights the interfacial SHA and provides a pathway to improve the functionality and performance of the next generation spintronic devices.