Recently, bulk spin-orbit torques (SOTs) in transition metal-rare earth (TM-RE) ferrimagnets have been reported. In this study, to investigate bulk SOTs, we observed the current-induced effective field mediated by a damping-like torque (DLT), which is one of the components of SOTs, using TM-RE ferrimagnetic Tbx(Gd32Fe68)100-x films with a Ta layer. The DLT efficiency ζDL was inactivated by increasing the Tb composition x to be greater than 8, suggesting that the DLT was induced by the bulk SOTs of Tbx(Gd32Fe68)100-x as well as the spin Hall effect in the Ta. However, from the DLT measurement using a Tb8(Gd32Fe68)92 layer sandwiched between Ru layers, where Ru has a negligibly small DLT, ζDL was almost zero. This indicates that the inactivation of DLT cannot simply be explained by the bulk SOTs of Tbx(Gd32Fe68)100-x. However, we expect that this finding will provide meaningful insights for controlling magnetization using current.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)