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 Pt_xRh_1−x/ferromagnet heterostructures, we find that the effective damping-like spin-torque efficiency and spin Hall conductivity are 0.18 and 3.8 × 10⁵ ℏ/2e Ω⁻¹ m⁻¹ for Pt_0.9Rh_0.1, respectively, with a low resistivity of 46.9 µΩ 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.

中文翻译：

---

PtRh /铁磁体异质结构中自旋轨道转矩的成分依赖性

我们通过改变PtRh合金的成分，通过实验研究了PtRh /异质结构中的自旋轨道转矩（SOT）。通过在铂进行DC偏置自旋扭矩铁磁谐振和二次谐波测量_X的Rh _1-X /铁磁异质结构，我们发现有效的阻尼状自旋扭矩效率和自旋霍尔电导率是0.18和3.8×10 ⁵ ℏ / 2 ë Ω ^-1 米^-1为铂_0.9铑_0.1分别与46.9的低电阻率μΩ厘米。此外，研究了电流引起的PtRh / Co中的SOT开关。SOT开关的临界电流密度随PtRh合金的Rh组成的增加而降低，这可以通过畴壁辅助开关来理解。由于大的自旋霍尔电导率，相对较低的电阻率以及高温工艺的可持续性，PtRh合金可能成为SOT应用中有吸引力的自旋源。