arXiv 2008.092322020-08cond-mat.mtrl-scicond-mat.str-el

具有可调各向异性的二维铁磁半导体VBr3

Two-dimensional ferromagnetic semiconductor VBr3 with tunable anisotropy

Lu Liu, Ke Yang, Guangyu Wang, Hua Wu

备注：: 8 pages, 8 figures, 2 tables
发表信息：: J. Mater. Chem. C, 8, 14782-14788 (2020)
DOI：: 10.1039/D0TC03962D

摘要：

二维铁磁体因其在自旋电子学中的应用前景而受到广泛关注。在这里，我们探索的电子结构和单层的VBr $_{3}$在蜂窝晶格中的磁性，使用第一性原理计算，晶体场能级分析，和Monte Carlo模拟。结果表明，VBr $_{3}$块材具有$e'_{g}$ $^2$（$S$ =1）基态，轨道磁矩小，面内磁各向异性弱.这些结果很好地解释了最近的实验。更有趣的是，我们发现，拉伸应变的半导体VBr $_{3}$单层调谐到$a_{1g}$ $^1$ $e'_{g}$ $^1$的基态，从而产生一个大的轨道时刻和强大的面外各向异性。然后，在2.5 $\%$ -5 $\%$应变下，显著增强的FM超交换和单离子各向异性（SIA）将使$T_{\rm C}$从裸VBr $_{3}$单层的20 K提高到100-115 K。因此，VBr $_{3}$将是一种有前途的具有可调各向异性的二维FM半导体。

英文摘要：

Two-dimensional (2D) ferromagnets (FMs) have attracted widespread attention due to their prospects in spintronic applications. Here we explore the electronic structure and magnetic properties of the bulk and monolayer of VBr$_{3}$ in the honeycomb lattice, using first-principles calculations, crystal field level analyses, and Monte Carlo simulations. Our results show that VBr$_{3}$ bulk has the $e'_{g}$$^2$ ($S$=1) ground state and possesses a small orbital moment and weak in-plane magnetic anisotropy. Those results well explain the recent experiments. More interestingly, we find that a tensile strain on the semiconducting VBr$_{3}$ monolayer tunes the ground state into $a_{1g}$$^1$$e'_{g}$$^1$ and thus produces a large orbital moment and a strong out-of-plane anisotropy. Then, the significantly enhanced FM superexchange and single ion anisotropy (SIA) would raise $T_{\rm C}$ from 20 K for the bare VBr$_{3}$ monolayer to 100-115 K under a 2.5$\%$-5$\%$ strain. Therefore, VBr$_{3}$ would be a promising 2D FM semiconductor with a tunable anisotropy.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文