Two-dimensional XY ferromagnetism above room temperature in Janus monolayer V2XN (X = P, As)

Wenhui Wan; Botao Fu; Chang Liu; Yanfeng Ge; Yong Liu

doi:10.1039/d3cp00088e

Two-dimensional XY ferromagnetism above room temperature in Janus monolayer V₂XN (X = P, As)

Phys Chem Chem Phys. 2023 Mar 29;25(13):9311-9319. doi: 10.1039/d3cp00088e.

Authors

Wenhui Wan¹, Botao Fu², Chang Liu³, Yanfeng Ge¹, Yong Liu¹

Affiliations

¹ State Key Laboratory of Metastable Materials Science and Technology & Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066004, P. R. China. yongliu@ysu.edu.cn.
² College of Physics and Electronic Engineering, Center for Computational Sciences, Sichuan Normal University, Chengdu, China.
³ Institute for Computational Materials Science, Joint Center for Theoretical Physics (JCTP), School of Physics and Electronics, Henan University, Kaifeng, 475004, China.

PMID: 36920148
DOI: 10.1039/d3cp00088e

Abstract

Two-dimensional (2D) XY magnets with easy magnetization planes support the nontrivial topological spin textures whose dissipationless transport is highly desirable for 2D spintronic devices. Here, we predicted that Janus monolayer V₂XN (X = P, As) with a square lattice is a 2D-XY ferromagnet using first-principles calculations. Both magnetocrystalline anisotropy and magnetic shape anisotropy favor an in-plane magnetization, leading to an easy magnetization xy-plane in Janus monolayer V₂XN. With the help of the Monte Carlo simulations, we observed the Berezinskii-Kosterlitz-Thouless (BKT) phase transition in monolayer V₂XN with the transition temperature T_BKT being above room temperature. In particular, monolayer V₂AsN has a magnetic anisotropy energy (MAE) of 292.0 μeV per V atom and a T_BKT of 434 K, which is larger than that of monolayer V₂PN. Moreover, a tensile strain of 5% can further improve the T_BKT of monolayer V₂XN to be above 500 K. Our results indicated that Janus monolayer V₂XN (X = P, As) can be candidate materials to realize high-temperature 2D-XY ferromagnetism for spintronics applications.