Sui Xuelei, Wang Jianfeng, Yam ChiYung, Huang Bing
Shenzhen JL Computational Science and Applied Research Institute, Shenzhen 518131, China.
Beijing Computational Science Research Center, Beijing 100193, China.
Nano Lett. 2021 May 12;21(9):3813-3819. doi: 10.1021/acs.nanolett.1c00172. Epub 2021 Apr 26.
Introducing magnetism to anionic electrons (AE) of electrides, especially for those confined in two-dimensional (2D) interlayer spaces, could provide a promising way to generate 2D spin-polarized free electron gas. However, the realization of this is challenging. Here, we propose a strategy for generating 2D magnetic AE, which requires two fundamental criteria, i.e., coexistence of localized AE (LAE) and delocalized AE (DAE) and a nearly half-filled LAE. Applying this to YC, the magnetism of 2D AE is tunable or sensitive to external strain, hole doping, and layer thickness, depending on the competition between atomic-orbital electrons, DAE, and LAE. Remarkably, a reversible on/off switching of magnetism can be achieved in bilayer YC by an electric field. Furthermore, the 2D magnetic AE in YC thin films are more robust against oxidation due to spatially selective hole doping effects. The manipulation of spin-polarized 2D AE gas paves a new way for designing spintronic devices with van der Waals magnets.
将磁性引入电子化合物的阴离子电子（AE）中，特别是对于那些限制在二维（2D）层间空间中的阴离子电子，可能为生成二维自旋极化自由电子气提供一种很有前景的方法。然而，实现这一点具有挑战性。在此，我们提出一种生成二维磁性AE的策略，这需要两个基本条件，即局域AE（LAE）和离域AE（DAE）共存以及LAE几乎半满。将此应用于YC时，二维AE的磁性是可调的，或者对外加应变、空穴掺杂和层厚度敏感，这取决于原子轨道电子、DAE和LAE之间的竞争。值得注意的是，通过电场可以在双层YC中实现磁性的可逆开/关切换。此外，由于空间选择性空穴掺杂效应，YC薄膜中的二维磁性AE对氧化更具抗性。自旋极化二维AE气体的操控为设计具有范德华磁体的自旋电子器件开辟了一条新途径。
