Determining spin-orbit torque in a single ferrimagnetic film without heavy metal via spin-torque ferromagnetic resonance

Abstract We report spin-orbit torque (SOT) in a single ferrimagnetic (FIM) GdFeCo alloy based on spin-torque ferromagnetic resonance (ST FMR). Thickness-dependent anomalous Hall resistance shows a bulk perpendicular magnetic anisotropy, which lead double peaks of ST FMR spectra at a larger thickness of 50 nm. Oblique-angle-dependent ST FMR is performed to study SOT, and the spin torque efficiency in the y axis is evaluated. This phenomenon is explained by the relationship between SOT and saturation magnetization. This finding provides an alternative method to modulate SOT in a single ferrimagnetic spintronic device.