The Origin of Strong Perpendicular Magnetic Anisotropy in a Ferromagnetic Fe3GaTe2 Monolayer

Magnetic anisotropy is pivotal for stabilizing ferromagnetic (FM) order against thermal fluctuations in two-dimensional (2D) systems. Motivated by the recent synthesis of the Fe3GaTe2 monolayer, we systematically investigate the origin of its strong perpendicular magnetic anisotropy (PMA) through first-principles calculations. Our results reveal that the robust PMA─persistent under external perturbations─originates from spin–orbit coupling (SOC)-driven hybridization between occupied and unoccupied px/py orbitals of Te atoms, with additional contributions from magnetic dipole–dipole interactions. Furthermore, dynamic stability (validated by phonon dispersion spectra), thermal stability (confirmed via ab initio molecular dynamics simulations), and mechanical stability (supported by elastic constants) collectively demonstrate the material’s structural robustness. These findings provide fundamental insights into the microscopic mechanisms governing the magnetic anisotropy in 2D magnetic materials.