Large magnetic anisotropy and strain induced enhancement of magnetic anisotropy in monolayer TaTe2

Abstract

Monolayer TaTe₂ holds great potential for the realization of large magnetocrystalline anisotropy due to strong spin–orbit coupling (SOC) interactions of Ta. Here, we systematically investigate the electronic structure, magnetism and magnetocrystalline anisotropy of monolayer TaTe₂ under different strains by means of first-principles calculations. The results show that monolayer TaTe₂ is a ferromagnetic metal and exhibits a large in-plane magnetic anisotropy energy (MAE) of −11.38 meV per TaTe₂. It is worth noting that the magnetic moment, magnetic coupling and magnetic anisotropy of monolayer TaTe₂ are significantly enhanced by strain. In particular, when tensile strain increases from 0% to 8%, the MAE of monolayer TaTe₂ greatly increases from −11.38 to −15.14 meV per TaTe₂. By analyzing the density of states and the contribution to magnetocrystalline anisotropy (MCA) from the SOC interaction between two d orbitals of Ta atoms based on second-order perturbation theory, it is concluded that a large MAE of monolayer TaTe₂ is mainly contributed by the SOC interaction between opposite spin d_xy and d_x²−y² orbitals of Ta atoms and the significant increase of the negative contribution to MCA from the SOC interaction between opposite spin d_xy and d_x²−y² orbitals under strain is the reason why the MAE of monolayer TaTe₂ is significantly enhanced by strain. Our results indicate that monolayer TaTe₂ is a promising candidate suitable for applications in magnetic storage devices.