Two-dimensional honeycomb-kagome V2X3 (X = O, S, Se) with half-metallicity, high Curie temperature, and large magnetic anisotropic energy

Abstract

Searching for intrinsic two-dimensional (2D) half-metal materials is a significant challenge for advanced spintronic applications. Here, we predict a series of stable 2D V₂X₃ (X = O, S, Se) monolayers with honeycomb-kagome (HK) structure with first-principles calculations, which exhibit intrinsic ferromagnetic (FM) ordering and considerably large magnetic anisotropy energy (MAE) of 130, 100, and 110 μeV per V atom for V₂O₃, V₂S₃, and V₂Se₃ monolayers, respectively. The first-principles linear response (FPLR) approach combined with Monte Carlo simulations suggests high Curie temperatures (T_C) of 459, 557, and 496 K for V₂X₃ (X = O, S, Se) monolayers, respectively. In addition, the 2D V₂X₃ (X = O, S, Se) monolayers expose highly desired half-metallicity wide band gaps in the spin-down channel of over 1 eV. Moreover, we investigate the effects on their MAE and magnetic ground state changes under the biaxial strain. Remarkably, all these monolayers are ferromagnetic in the ground state but undergo antiferromagnetic (AFM) phase transition under the influence of −2.8%, −2.3%, and −3.4% compressive strain for V₂X₃ (X = O, S, Se) monolayers, respectively. Overall, our prediction of such intrinsic 2D FM half-metal V₂X₃ (X = O, S, Se) monolayers may serve as a good candidate for high-performance spintronic nanodevices.