Wan Wenhui, Fu Botao, Liu Chang, Ge Yanfeng, Liu Yong
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.
College of Physics and Electronic Engineering, Center for Computational Sciences, Sichuan Normal University, Chengdu, China.
Phys Chem Chem Phys. 2023 Mar 29;25(13):9311-9319. doi: 10.1039/d3cp00088e.
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 VXN (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 -plane in Janus monolayer VXN. With the help of the Monte Carlo simulations, we observed the Berezinskii-Kosterlitz-Thouless (BKT) phase transition in monolayer VXN with the transition temperature being above room temperature. In particular, monolayer VAsN has a magnetic anisotropy energy (MAE) of 292.0 μeV per V atom and a of 434 K, which is larger than that of monolayer VPN. Moreover, a tensile strain of 5% can further improve the of monolayer VXN to be above 500 K. Our results indicated that Janus monolayer VXN (X = P, As) can be candidate materials to realize high-temperature 2D-XY ferromagnetism for spintronics applications.
具有易磁化平面的二维（2D）XY磁体支持非平凡的拓扑自旋纹理，其无耗散输运对于二维自旋电子器件非常理想。在此，我们通过第一性原理计算预测，具有方形晶格的Janus单层VXN（X = P，As）是一种二维XY铁磁体。磁晶各向异性和磁形状各向异性都有利于面内磁化，导致Janus单层VXN中存在易磁化平面。借助蒙特卡罗模拟，我们在单层VXN中观察到了 Berezinskii-Kosterlitz-Thouless（BKT）相变，其转变温度高于室温。特别是，单层VAsN每个V原子的磁各向异性能量（MAE）为292.0 μeV，转变温度为434 K，大于单层VPN的转变温度。此外，5%的拉伸应变可进一步将单层VXN的转变温度提高到500 K以上。我们的结果表明，Janus单层VXN（X = P，As）可作为实现用于自旋电子学应用的高温二维XY铁磁性的候选材料。
