Enhancement of spin transparency by interfacial alloying

TL;DR

This paper demonstrates that atomic-layer alloying at a Pt/Co interface enhances spin transparency and spin-orbit torque efficiency, offering a new method to improve spintronic device performance.

Contribution

It introduces interfacial alloying as a novel approach to increase spin transparency and torque efficiency in heavy-metal/ferromagnet interfaces.

Findings

Interfacial alloying increases spin transparency by ~30%.

Alloying enhances dampinglike spin-orbit torque efficiency.

Fieldlike spin-orbit torque is substantially reduced.

Abstract

We report that atomic-layer alloying (intermixing) at a Pt/Co interface can increase, by approximately 30%, rather than degrade the interfacial spin transparency, and thereby strengthen the efficiency of the dampinglike spin-orbit torque arising from the spin Hall effect in the Pt. At the same time, this interfacial alloying substantially reduces fieldlike spin-orbit torque. Insertion of an ultrathin magnetic alloy layer at heavy-metal/ferromagnet interfaces represents an effective approach for improving interfacial spin transparency that may enhance not only spin-orbit torques but also the spin detection efficiency in inverse spin Hall experiments.