Liu Tian, Zhou Na, Li Xu, Zhu Guojun, Wei Xiaolin, Cao Juexian
School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, People's Republic of China.
J Phys Condens Matter. 2019 Jul 24;31(29):295801. doi: 10.1088/1361-648X/ab1885. Epub 2019 Apr 11.
In virtue of first principle calculations based on density functional theory, we have investigated the magnetism of transition metal triiodides XI (X = Cr, Mn, Fe, Mo, Tc, Ru, W, Re, Os) monolayers. Our results indicate that CrI, TcI, RuI, ReI and OsI monolayers are ferromagnetic (FM), while MnI, FeI, MoI and WI monolayers are antiferromagnetic (AFM). Interestingly, TcI, RuI, ReI and OsI monolayers have considerable magnetic anisotropy energy (MAE). Especially, ReI monolayer exhibits the largest MAE (-36.22 meV/ReI) in known two-dimensional (2D) van der Waals (vdW) crystals. We further demonstrate that biaxial strain can greatly change MAEs of ReI and OsI monolayers. From the electronic structure analysis, the change in MAE is mainly attributed from the charge transfer between the a and e states induced by biaxial strain. In addition, we have also found that a tensile strain can lead to a phase transition of ReI from FM to AFM. We predicted that 2D FM XI monolayers are promising candidates for the application in tunable magnetic storage technology.
基于密度泛函理论的第一性原理计算，我们研究了过渡金属三碘化物XI（X = Cr、Mn、Fe、Mo、Tc、Ru、W、Re、Os）单层的磁性。我们的结果表明，CrI、TcI、RuI、ReI和OsI单层是铁磁性的（FM），而MnI、FeI、MoI和WI单层是反铁磁性的（AFM）。有趣的是，TcI、RuI、ReI和OsI单层具有相当大的磁各向异性能量（MAE）。特别是，ReI单层在已知的二维（2D）范德华（vdW）晶体中表现出最大的MAE（-36.22 meV/ReI）。我们进一步证明，双轴应变可以极大地改变ReI和OsI单层的MAE。从电子结构分析来看，MAE的变化主要归因于双轴应变引起的a和e态之间的电荷转移。此外，我们还发现拉伸应变会导致ReI从FM相转变为AFM相。我们预测二维FM XI单层是可调谐磁存储技术应用的有前途的候选材料。
