Large magnetic anisotropy and enhanced Curie temperature in two-dimensional MnTe2 coupled with β-phase group-VA semiconductor monolayers

Promoting the Curie temperature (TC) and tunning the magnetocrystalline anisotropy energy (MAE) have been key issues with two-dimensional (2D) ferromagnetic (FM) materials. Here, the structural and magnetic properties of MnTe2/X (X = As, Sb and Bi) heterostructures are investigated through first-principles calculations. We reveal that monolayer MnTe2 weakly interacts with monolayer As or Sb through van der Waals (vdW) forces, but has strong covalent bonds with monolayer Bi, indicated by Bi–Te bond formation. The coupling of MnTe2 with these β-phase group-VA semiconductor monolayers substantially modulates MAE, with MnTe2/As showing a shift to in-plane easy magnetization, and MnTe2/Sb exhibiting a large perpendicular MAE of 4.13 meV per cell. The formation of vdW heterostructures influence on Te spin–orbit coupling matrix elements markedly governs MAE. MnTe2/Bi also has an in-plane MAE, contributed by both Te and Bi atoms. Additionally, coupling MnTe2 with X significantly affects magnetic interactions. It is worth noting that the TC of MnTe2/Sb reaches 233.2 K, significantly larger than that of pure MnTe2. A large perpendicular MAE and a heightened TC makes MnTe2/Sb desired candidates for next-generation spintronic applications. Our work provides a way to modulate the magnetic properties of 2D FM materials.