Strain- and Carrier-Engineered Electromagnetic Properties in Transition-Metal Chalcogenide Monolayers: Implications for Nanoscale Spintronic Devices

Magnetic semiconductors, which are characterized by strong magnetic coupling and semiconducting features, have the potential to be applied in spintronic devices. Here, a family of TM3X5 (TM = V, Fe, Co, Ni; X = O, S, Se) monolayers were predicted to be robust magnetic semiconductors based on first-principles calculations. Our findings show that the V3Se5 monolayer exhibits ferromagnetic (FM) semiconductor character, while Fe3S5, Co3O5, and Ni3O5 monolayers are found to be antiferromagnetic (AFM) semiconductors. Among them, the FM order in the V3Se5 monolayer is ultraly stable with a high Curie temperature of 500 K, which can be enhanced to 900 K under 2% tensile strain. Moreover, the electronic and magnetic properties of these TM3X5 monolayers are sensitive to carrier doping. The Ni3O5 monolayer can be transformed to an AFM half-metal or an AFM bipolar magnetic semiconductor under electron or hole doping, respectively. Such properties endow TM3X5 monolayers with tremendous potential for practical applications in the realm of nanoscale spintronic devices.