论文标题
固有的铁磁性和限制性热力学稳定性，$ _2 $ n $ _4 $和JANUS VSIGEN $ _4 $ MONOLAYERS
Intrinsic ferromagnetism and restrictive thermodynamic stability in MA$_2$N$_4$ and Janus VSiGeN$_4$ monolayers
论文作者
论文摘要
The seminal experimental discovery of the remarkably stable MoSi$_2$N$_4$ monolayer has led to a handful of predicted magnetic two-dimensional (2D) materials in the MA$_2$Z$_4$ family (M = transition metals, A = Si, Ge, and Z = N, P, As).预计这些磁性单层是动态稳定的，但迄今为止均未合成它们。在这封信中，从第一原理热力学稳定性分析中，我们证明了只有硝酸盐在热力学上是稳定的，并且在富含N的条件下发生。基于这一发现，我们提出了两个家庭中的janus单层：Vsigen $ _4 $和VSISNN $ _4 $。它们既动态稳定又有热稳定，但只有前者在热力学上稳定。有趣的是，Janus vsigen $ _4 $和VSISNN $ _4 $单层显示面板内各向异性较弱，而VSI $ _2 $ _2 $ n $ _4 $ _4 $单层。这两个新兴的Janus磁性半导体为研究2D磁性和用于Spintronics应用的自旋控制提供了机会。
The seminal experimental discovery of the remarkably stable MoSi$_2$N$_4$ monolayer has led to a handful of predicted magnetic two-dimensional (2D) materials in the MA$_2$Z$_4$ family (M = transition metals, A = Si, Ge, and Z = N, P, As). These magnetic monolayers were predicted to be dynamically stable, but none of them has been synthesized to date. In this Research Letter, from first-principles thermodynamic stability analysis, we demonstrate that only the nitrides are thermodynamically stable and this occurs under N-rich conditions. Based on this finding, we propose two ferromagnetic, semiconducting Janus monolayers in the family: VSiGeN$_4$ and VSiSnN$_4$. They are both dynamically and thermally stable, but only the former is thermodynamically stable. Intriguingly, Janus VSiGeN$_4$ and VSiSnN$_4$ monolayers show weak in-plane anisotropy compared with the VSi$_2$N$_4$ monolayer. These two emerging Janus magnetic semiconductors offer opportunities for studying 2D magnetism and spin control for spintronics applications.
