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arXiv · 1809.02828

Irrelevance of magnetic proximity effect to spin-orbit torques in heavy metal/ferromagnet bilayers

L. J. Zhu·D. C. Ralph·R. A. Buhrman
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Abstract

The magnetic proximity effect (MPE) is a well-established magnetic phenomenon that occurs at certain heavy metal (HM)/ferromagnet (FM) interfaces. However, there is still an active debate as to whether the presence of a MPE affects spin transport through such a HM/FM interface. Here we demonstrate that the MPE at Pt/Co and Au0.25Pt0.75/Co interfaces can be enhanced substantially by thermal annealing protocols. From this ability, we show that the MPE has no discernable influence on either the damping-like or the field-like spin-orbit torques exerted on the FM layer due to the spin Hall effect of the HM layer, indicating a minimal role of the MPE compared to other interfacial effects, e.g. spin memory loss and spin backflow.

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L. J. Zhu, D. C. Ralph, R. A. Buhrman. 2018-09-08. Irrelevance of magnetic proximity effect to spin-orbit torques in heavy metal/ferromagnet bilayers. https://doi.org/10.1103/physrevb.98.134406

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