Magnetization-dependent inverse spin Hall effect in compensated ferrimagnet TbCo alloys

Abstract

In this paper, we demonstrate the magnetization-dependent inverse spin Hall effect (MD-ISHE) in ${\mathrm{Tb}}_{x}{\mathrm{Co}}_{100\ensuremath{-}x}/\mathrm{Pt}/{\mathrm{Y}}_{3}{\mathrm{Fe}}_{5}{\mathrm{O}}_{12}$ devices using the spin Seebeck effect. It was found that a thermally injected spin current is precessed around the magnetization of the ${\mathrm{Tb}}_{x}{\mathrm{Co}}_{100\ensuremath{-}x}$ alloy before it is converted into a charge current. Furthermore, the sign of the MD-ISHE voltage was found to depend on the Co magnetic moment direction, whereas the sign and magnitude of the conventional ISHE voltage are independent of the ${\mathrm{Tb}}_{x}{\mathrm{Co}}_{100\ensuremath{-}x}$ magnetization direction. Meanwhile, the spin rotation angle was estimated to be \ensuremath{\sim}12% in ${\mathrm{Tb}}_{x}{\mathrm{Co}}_{100\ensuremath{-}x}/\mathrm{Pt}$. Our findings demonstrate that perpendicularly magnetized ${\mathrm{Tb}}_{x}{\mathrm{Co}}_{100\ensuremath{-}x}$ supplies additional symmetry to the ISHE and provides advantages in terms of tailoring the sign of the spin-current polarization through adjusting the alloy composition.