Engineering Mn₃Ga/GaAs interfaces: a first-principles study on energetic stability and magnetic anisotropy

Mn 3 Ga-based ferrimagnets have emerged as a promising platform for energy-efficient spintronics. However, the challenge of identifying an appropriate substrate with minimal lattice misfit for the growth of high-quality Mn 3 Ga films while achieving the desired interfacial magnetic properties persists. Here we investigate the interfacial energetic stability and magnetic anisotropy at the Mn 3 Ga/GaAs interface through first-principles electronic structure calculations. Four types of interface models based on different configurations, including MnMn/As, MnMn/Ga, MnGa/As, and MnGa/Ga, are systematically examined. Our findings reveal that the MnGa/Ga interface exhibits the largest perpendicular magnetic anisotropy (PMA) but is energetically the least favorable. Conversely, the MnMn/As interface is energetically the most favorable but demonstrates a lower interfacial PMA. Our calculations align well with the experimentally observed formation of the secondary phase Mn 2 As. This study deepens our understanding of the interfacial properties in Mn 3 Ga/GaAs and offers some insights for their optimization through strategic interfacial engineering.