Tuning magnetic properties of single-layer MnTe2 via strain engineering

Abstract

We systematically study the strain-tuning effect on the electronic and magnetic properties of single-layer MnTe2 using first-principles calculations. The calculations show that the unstrained single-layer MnTe2 is an intrinsic ferromagnetic metal with a perpendicular magnetocrystalline anisotropy. The in-plane biaxial tensile strain greatly enhances the perpendicular magnetocrystalline anisotropy. The orbital-projected spin-orbit coupling energy indicates that the magnetocrystalline anisotropy energy mainly comes from the contribution of the Te atom although its magnetic moment is small. The ferromagnetic interaction between the nearest two Mn atoms is also strengthened significantly by the tensile strain. The Curie temperature increases from 88 K without strain to 440 K at 10% strain. Moreover, the single-layer MnTe2 becomes a half metal when the tensile strain is larger than 6%. If compressive strain is applied, the single-layer MnTe2 undergoes a spin reorientation transition from out-of-plane to in-plane magnetization. The compressive strain also induces the transition of the Mn–Mn exchange coupling from ferromagnetic to antiferromagnetic. The intrinsic ferromagnetic properties and the strong strain-tuning effect make the single-layer MnTe2 a promising candidate for spintronics applications.