Inverse spin Hall effect and spin pumping in the polycrystalline noncollinear antiferromagnetic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Mn</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mi>Ga</mml:mi></mml:mrow></mml:math>

Abstract

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 (${g}_{\mathrm{eff}}^{\ensuremath{\uparrow}\ensuremath{\downarrow}})$, spin Hall angle $({\ensuremath{\theta}}_{SH})$, and spin Hall conductivity (${\ensuremath{\sigma}}_{SH}$) are evaluated to be $(5.0\ifmmode\pm\else\textpm\fi{}1.8)\ifmmode\times\else\texttimes\fi{}{10}^{18}\phantom{\rule{0.16em}{0ex}}{\mathrm{m}}^{\ensuremath{-}2}, 0.31\ifmmode\pm\else\textpm\fi{}0.01$, and $7.5\ifmmode\times\else\texttimes\fi{}{10}^{5}\phantom{\rule{0.28em}{0ex}}(\ensuremath{\hbar}/2e)\phantom{\rule{0.16em}{0ex}}{\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}1\phantom{\rule{4pt}{0ex}}}\phantom{\rule{0.16em}{0ex}}{\mathrm{m}}^{\ensuremath{-}1}$, respectively. The observed value of ${\ensuremath{\theta}}_{SH}$ 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.

Topics & Concepts