Tunable spin-orbit torques and perpendicular magnetic anisotropy at oxidized Al/Co interfaces

Abstract

We investigated the correlation between perpendicular magnetic anisotropy (PMA) and spin-orbit torques (SOTs) originating at oxidized Al/Co interfaces with various interfacial oxidation levels. We found that both interfacial PMA and interfacial SOTs are maximized by tuning the interfacial oxidation level. The observed tunability of the interfacial PMA is consistent with previous reports, where the origin of the maximization is attributed to the appearance of the electronic hybridization between the O orbitals and Co orbitals in combination with the spin-orbit coupling. The tunable interfacial PMA and interfacial SOT are found to be positively correlated, which suggests that the underlying mechanism behind the interfacial PMA also plays an essential role in the generation of the interfacial SOT.