2D-XY ferromagnetism with high transition temperature in Janus monolayer V\(_{2}\)XN (X = P, As)

• Published in: arXiv.org 2023-02
• Main Authors: Wan, Wenhui, Fu, Botao, Liu, Chang, Guo, Rui, Ge, Yanfeng, Liu, Yong
• Format: Article
• Language: English
• Subjects: Electron spin; Energy dissipation; Ferromagnetism; First principles; Magnetic anisotropy; Magnetic materials; Magnetic properties; Magnetism; Magnets; Materials selection; Monolayers; Phase transitions; Spintronics; Tensile strain; Transition temperature
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2208.06745

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 V\(_{2}\)XN (X = P, As) with a square lattice are 2D-XY ferromagnets by first-principles calculations. Both the magnetocrystalline anisotropy and magnetic shape anisotropy favor an in-plane magnetization, leading to an easy magnetization \(xy\)-plane in Janus monolayer V\(_{2}\)XN. Resting on the Monte Carlo simulations, we observed the Berezinskii-Kosterlitz-Thouless (BKT) phase transition in monolayer V\(_{2}\)XN with transition temperature \(T_{\rm BKT}\) being above the room temperature. Especially, monolayer V\(_{2}\)AsN has a magnetic anisotropy energy (MAE) of 292.0 \(\mu\)eV per V atom and a \(T_{\rm BKT}\) of 434 K, which is larger than that of monolayer V\(_{2}\)PN. Moreover, a tensile strain of 5\% can further improve the \(T_{\rm BKT}\) of monolayer V\(_{2}\)XN to be above 500 K. Our results indicated that Janus monolayer V\(_{2}\)XN (X = P, As) were candidate materials to realize high-temperature 2D-XY ferromagnetism for spintronics applications.