Spin-orbit torque induced magnetization switching in ferrimagnetic Heusler alloy DO_(22)-Mn_3Ga with large perpendicular magnetic anisotropy

摘要

Magnetization switching induced by spin-orbit torque is of fundamental interest for developing spintronic devices with low-power consumption and nonvolatility. Here, we report on the spin-orbit torque induced magnetization switching behavior of (001) oriented tetragonal Heusler alloy D0(22)-Mn3Ga films with an intrinsic ferrimagnetic spin structure grown on the GaAs(001) substrate by molecular-beam epitaxy. The out-of-plane hysteresis loop and anomalous Hall effect demonstrated a large perpendicular magnetic anisotropy and low saturation magnetization of D0(22)-Mn3Ga thin films. The spin-orbit torque induced magnetization switching has been realized in D0(22)-Mn3Ga/Pt heterostructure based Hall devices under an in-plane external field. It is found that the critical switching current density J(c) is much smaller than that of the L1(0)-MnGa/heavy metal system. Besides, both a dampinglike effective field H-DL and a fieldlike effective field H-FL are quantified by performing harmonic Hall voltage measurements. All these results indicate that ferrimagnetic D0(22)-Mn3Ga can be a promising candidate material for realizing high-density and energy-efficient spintronic devices.