Magnetism and magnetocrystalline anisotropy in single-layer PtSe2: Interplay between strain and vacancy

The electronic and magnetic properties of the newly synthesized single-layer (1 L) transition-metal dichalcogenide (TMD) PtSe2 are studied by first-principles calculations. We find the strain or selenium vacancy (V-Se) alone cannot induce the magnetism. However, an interplay between strain and V-Se leads to the magnetism due to the breaking of Pt-Pt metallic bonds. Different from the case of 1 L-MoS2 with V-S, the defective 1 L-PtSe2 has the spatially extended spin density, which is responsible for the obtained long range ferromagnetic coupling. Moreover, the 1 L-PtSe2 with V-Se undergoes a spin reorientation transition from out-of-plane to in-plane magnetization, accompanying a maximum magnetocrystalline anisotropy energy of similar to 9-10.6 me V/V-Se. These results indicate the strain not only can effectively tune the magnetism but also can manipulate the magnetization direction of 1 L-TMDs. Published by AIP Publishing.