Spin–Orbit Torque Switching of a High-Quality Perpendicularly Magnetized Ferrimagnetic Heusler Mn₃Ge Film

Current-induced spin–orbit torque (SOT) switching of magnetization has attracted great interest due to its potential application in magnetic memory devices, which offer low-energy consumption and high-speed writing. However, most of the SOT studies on perpendicularly magnetized anisotropy (PMA) magnets have been limited to heterostructures with interfacial PMA and poor thermal stability. Here, we experimentally demonstrate a SOT magnetization switching for a ferrimagnetic D0₂₂-Mn₃Ge film with high bulk PMA and robust thermal stability factor under a critical current density of 6.6 × 10¹¹ A m^–2 through the spin Hall effect of an adjacent capping Pt and a buffer Cr layer. A large effective damping-like SOT efficiency of 2.37 mT/10¹⁰ A m^–2 is determined using harmonic measurements in the structure. The effect of the double-spin source layers and the negative-exchange interaction of the ferrimagnet may explain the large SOT efficiency and the manifested magnetization switching of Mn₃Ge. Our findings demonstrate that D0₂₂-Mn₃Ge is a promising candidate for application in high-density SOT magnetic random-access memory devices.