Controllable half-metallicity in MnPX₃ monolayer

Modulable electronic and magnetic structures significantly extend the properties and applications of two-dimensional (2D) materials. 2D antiferromagnets (AFM) can even become ferromagnets (FM) by various approaches, which ignites growing research interests in 2D AFM. Through first-principles calculations, we find that the adsorption of Li (electron doping) and F (hole doping) on the surface of MnPSe₃ can induce half-metallicity with opposite spin polarizations. The adsorption site, concentration, charge transfer, and the exchange energy are investigated in detail, indicating the robustness of half-metallicity. At the interface of MnPS₃/Au(111) heterostructure, we find electrons transfer from Au(111) to MnPS₃, forming the Ohmic contact and inducing AFM-FM transition. All our results show that ferromagnetic MnPX₃ (X = S and Se) monolayer with half-metallicity can be easily obtained, which may be of great significance in 2D spintronic materials and devices.