Composition dependence of spin-orbit torques in PtRh/ferromagnet heterostructures

We experimentally study the spin-orbit torque (SOT) in PtRh/heterostructures by varying the composition of PtRh alloy. By performing dc-biased spin-torque ferromagnetic resonance and second-harmonic measurements in PtxRh1-x/ferromagnet heterostructures, we find that the effective damping-like spin-torque efficiency and spin Hall conductivity are 0.18 and 3.8 x 10(5)/2e Omega (-1) m(-1) for Pt0.9Rh0.1, respectively, with a low resistivity of 46.9 mu Omega cm. Furthermore, current induced SOT switching in PtRh/Co is investigated. The critical current density for SOT switching decreases with an increase in the Rh composition of the PtRh alloy, which can be understood by domain wall assisted switching. Due to a large spin Hall conductivity, a relatively low resistivity, and sustainability of the high temperature process, the PtRh alloy could be an attractive spin source for SOT applications.

Automated summary

The study investigated the spin-orbit torque in PtRh alloy and found that Pt0.9Rh0.1 exhibits high spin torque efficiency and spin Hall conductivity. The critical current density for SOT switching in PtRh alloy decreases as the Rh composition increases.