Magnetism in substitutionally doped TMDs: magnetic ground states and critical temperatures

Recent experimental advances in the field of two-dimensional (2D) magnetism have led to new avenues of realizing 2D magnets and their applications. A wide variety of 2D Transition-metal dichalcogenides (TMDs) doped with period four transition metals are expected to show magnetic order. The larger spin-orbit coupling in heavier TMDs (e.g., MoSe₂) and their larger bandgaps open up the possibility to realize localized magnetic semiconductors through substitutional doping. Moreover, the magnetic order in TMDs through metal dopants is a charge driven phenomenon, which can be controlled via an external electric field, making transition-metal doped TMDs very attractive for future applications. In this work, we theoretically model the magnetic structure of TMDs (MoSe₂, WSe₂, MoS₂, WS₂, and MoTe₂) substitutionally doped with all period four metals (Ti, V, Cr, Mn, Fe, Co, and Ni), using a combination of density functional theory and the Monte-Carlo algorithm. We calculate the magnetic ground state and the critical temperature for each dopant-TMD combination. We show that the magnetic stable states of the TMD fall in five distinct categories. Finally, we show that doping MoSe₂ and WSe₂ with vanadium (V), results in a room-temperature (>300K) ferromagnet at a doping concentration of 5-6%.