Strain-controllable high Curie temperature and magnetic anisotropy energy in monolayers MnAsBr and MnAsI

Abstract The coexistence of intrinsic ferromagnetism and high Curie temperature is critical for advanced multifunctional spintronic technologies. Two-dimensional (2D) ferromagnetic (FM) materials, which enable simultaneous control of charge and spin degrees of freedom, represent a promising solution to this challenge. Using first-principles calculations and Monte Carlo simulations, we investigate strain-regulated magnetic properties—specifically magnetic anisotropy energy (MAE) and Curie temperature (T C ) of MnAsBr and MnAsI monolayers (MLs). Our calculations reveal out-of-plane magnetic anisotropy energies (MAE) of 0.90 meV and 2.87 meV per unit cell for MnAsBr and MnAsI MLs, respectively, with corresponding Curie temperatures of 439 K and 522 K. Under 5% tensile strain, the MAE increases to 1.58 meV (MnAsBr) and 3.14 meV (MnAsI), while T C rises to 505 K and 544 K for the respective ML systems. These findings demonstrate that MnAsBr and MnAsI monolayers are compelling candidates for flexible spintronic devices.