Effective Modulating the Electronic and Magnetic Properties of VI3 Monolayer: A First-Principles Calculation

Exploring a two-dimensional ferromagnetic material with a high Curie temperature and large magnetic anisotropy energy is still challenging. Here, we implement an effective adjustment on the electronic and magnetic properties of VI3 monolayer by means of first-principles calculation. The results indicate that the most stable structure of VI3 monolayer is particularly susceptible to the calculation parameter such as Hubbard U and the spin-orbit coupling (SOC). Ultimately, under density functional theory (DFT) +U + SOC (U = 3 eV), the most stable structure of VI3 monolayer is a ferromagnetic semiconductor with a direct band gap of 0.51 eV, and the predicted Curie temperature (T-C) is 29 K. Biaxial strain and carrier doping could not only induce VI3 monolayer FM-AFM-FM transition, but also effectively increase T-C to 123 K under 0.5 electron doping. Meanwhile, carrier hoping realizes the potential ferromagnetic half-metal. Fortunately, in the constructing alloy monolayer, the VTaI6 monolayer is found a ferromagnetic half-metal under DFT + U (U = 3, 1 eV for V and Ta), and the T-C is increased to 74 K. Moreover, VTaI6 monolayer possesses a large in-plane magnetic anisotropy energy (IMA) and its physical origin is explained in detail based on the second-order perturbation theory. These findings suggest that VI3 monolayer has a potential application in the spintronics and high-density magnetic storage devices.