Noncollinear antiferromagnetic (AFM) materials have drawn research interest because they exhibit large anomalous Hall effect at room temperature (RT) due to large Berry curvature. ${\mathrm{Mn}}_3\mathrm{Ga}$ is a noncollinear AFM in which the order of Mn magnetic moments is arranged in inverse triangular configuration on a kagome lattice. It makes ${\mathrm{Mn}}_3\mathrm{Ga}$ a promising candidate for inverse spin Hall effect (ISHE) study which has not been studied before. In this work, investigation of ISHE and spin pumping in polycrystalline ${\mathrm{Mn}}_3\mathrm{Ga}$/CoFeB heterostructures at RT has been performed. Angle-dependent measurements of ISHE have been performed in order to disentangle various spin-rectification effects. Spin-mixing conductance ($g_{\mathrm{eff}}^{\uparrow \downarrow })$, spin Hall angle $\left({\theta }_{SH}\right)$, and spin Hall conductivity (${\sigma }_{SH}$) are evaluated to be $(5.0\pm 1.8)\times {10}^{18}{\mathrm{m}}^{-2}, 0.31\pm 0.01$, and $7.5\times {10}^5(\hslash /2e){\mathrm{\Omega }}^{-1}{\mathrm{m}}^{-1}$, respectively. The observed value of ${\theta }_{SH}$ is higher than ${\mathrm{Mn}}_3\mathrm{Sn}$ and comparable to the ${\mathrm{IrMn}}_3$, which is also a noncollinear AFM. Large spin Hall angle makes ${\mathrm{Mn}}_3\mathrm{Ga}$ a promising candidate for future spintronics devices.

• Received 28 August 2020
• Revised 4 November 2020
• Accepted 9 November 2020

DOI:https://doi.org/10.1103/PhysRevB.102.174444