Theoretical prediction of two-dimensional ferromagnetic Mn2X2 (X = As, Sb) with strain-controlled magnetocrystalline anisotropy

Abstract

Two-dimensional (2D) magnetic materials with large and tunable magnetocrystalline anisotropy (MCA) provide unique opportunities to develop various spintronic devices. We, herein, propose an experimentally feasible 2D material platform, Mn₂X₂ (X = As, Sb), which is a family of intrinsic ferromagnet. Using first-principles calculations, we show that 2D Mn₂X₂ (X = As, Sb) with a robust ferromagnetic ground state exhibits not only a large perpendicular magnetic anisotropy (PMA), but also significant strain-driven modulation behaviors under external biaxial strain. The analysis of the results demonstrates that the dominant contribution to the change of MCA of Mn₂As₂ and Mn₂Sb₂ primarily arises from the Mn and Sb atoms, respectively. Moreover, we reveal that the underlying origin is the competitive mechanism for the spin–orbit coupling (SOC) between different orbitals and spin channels. These findings indicate that 2D Mn₂X₂ (X = As, Sb) provides a promising material platform for the next generation of ultra-low energy memory devices.