Magnetization switching induced by magnetic field and electric current in perpendicular TbIG/Pt bilayers

Abstract

Magnetic insulators (MIs) have attracted great attention because of their low Gilbert damping, long spin transmission length, and no Ohmic loss. In this study, the high quality TbIG films with perpendicular magnetic anisotropy were epitaxially grown on GGG (111) substrates. In TbIG/Pt bilayers, the angular dependence of coercivity is found to obey the Kondorsky model, suggesting the magnetization reversal mechanism of magnetic domain nucleation and expansion. The transverse component of spin Hall magnetoresistance (SMR), which is analogous to the planar Hall resistance in a ferromagnetic metal, is found to be about seven times larger than the SMR-induced anomalous Hall resistance (analogous to the anomalous Hall resistance in a ferromagnetic metal). Moreover, the phase diagrams of the current-induced magnetization switching with different angles and magnitudes of the assisting magnetic field were drawn for the TbIG/Pt bilayers. The current-induced damping-like effective field (HDL) characterized by the harmonic measurements was evaluated to be about 164 Oe/108 A cm−2. By providing a comprehensive investigation of magnetization switching behaviors in MIs, our results will promote the application of ultralow-dissipation MI based spintronic devices.