Magnetic properties of monolayer VS2 with or without point defects

Two-dimensional (2D) transition metal dichalcogenides (TMDs) are becoming increasingly attractive and beneficial to the development of spintronic devices and integrated circuit technologies. The magnetism of monolayer vanadium disulfide remains debated, with no consensus on whether it exhibits ferromagnetism or remains non-magnetic at room temperature. Herein, based on first-principles calculations, we study the stability and electronic structure of monolayer VS₂ in the 1T and 2H phases. Both phases are ferromagnetic ordering in the ideal structure and the magnetic exchange parameters are obtained through the spin-spiral method. Moreover, through the Monte Carlo simulator, we simulate the variation of magnetic parameters along with the increase in temperature. Finally, according to the Stoner criterion, the magnetic moment around the V point defect may collapse due to the decrease in the density of states at the Fermi level. This provides a theoretical explanation for the prevalent absence of observation of net magnetic moments in experiments.