Diverse Spin-Polarized In-Gap States at Grain Boundaries of Rhenium Dichalcogenides Induced by Unsaturated Re–Re Bonding,ACS Materials Letters

当前位置： X-MOL 学术 › ACS Mater. Lett. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Diverse Spin-Polarized In-Gap States at Grain Boundaries of Rhenium Dichalcogenides Induced by Unsaturated Re–Re Bonding
ACS Materials Letters ( IF 9.6 ) Pub Date : 2021-09-20 , DOI: 10.1021/acsmaterialslett.1c00418
Xiya Chen ₁ , Bao Lei _{1,

2} , Yong Zhu ₁ , Jiadong Zhou ₃ , Meng Gao ₁ , Zheng Liu ₃ , Wei Ji ₂ , Wu Zhou _{1,

4}

Affiliation

Grain boundaries (GBs) are important structural defects that have significant influence on the electronic structure and magnetic properties of transition-metal dichalcogenides (TMDs). However, reports on GBs in lower-symmetry T″-structure TMDs, especially on their local electronic structures, are rare. Here, we report a systematic study of intrinsic coherent GBs in monolayer ReSe₂, a representative T″-structure TMD with anisotropy and intriguing electrical properties, via a combination of atomic-resolution scanning transmission electron microscopy (STEM) imaging and first-principles calculations. These coherent GBs feature a coherent Se sublattice and unchanged Re–Se (and Se–Re) local coordination. Based on the saturation of the Re–Re bond, the GBs are divided into three categories: those with saturated Re–Re bonds (3 Re–Re bonds per Re atom), denoted as α-GBs; those with truncated Re4 chains but intact Re4 clusters (β-GBs); and those with broken Re4 clusters (γ-GBs). The intact configurations of the α-GBs enable them to form easily, and they possess semiconductor characteristics inherited from the pristine ReSe₂ monolayer. Interestingly, the introduction of both β-GBs and γ-GBs leads to the emergence of local magnetic moment, arising from the Re 5d_xz atomic orbitals around the boundaries. Moreover, the GBs with broken Re–Re bonds (β- and γ-GBs) exhibit subtle differences in spin-polarized in-gap states, demonstrating the strong dependency of the electronic properties on the precise atomic structure of the GBs. These results are of fundamental importance in understanding lower-symmetry TMDs and the structure–property relationships in two-dimensional materials.

中文翻译：

由不饱和 Re-Re 键合诱导的铼二硫属化物晶界处的不同自旋极化 In-Gap 态

晶界（GBs）是重要的结构缺陷，对过渡金属二硫属化物（TMDs）的电子结构和磁性能有显着影响。然而，关于低对称性 T" 结构 TMD 中 GB 的报道，特别是关于其局部电子结构的报道很少。在这里，我们报告了对单层 ReSe ₂中内在相干 GB 的系统研究，通过原子分辨率扫描透射电子显微镜（STEM）成像和第一性原理计算的组合，具有各向异性和有趣的电特性的代表性T”结构TMD。这些相干 GB 具有相干的 Se 亚晶格和不变的 Re-Se（和 Se-Re）局部协调。根据 Re-Re 键的饱和度，GBs 分为三类：具有饱和 Re-Re 键的 GBs（每个 Re 原子有 3 个 Re-Re 键），表示为 α-GBs；那些具有截断的 Re4 链但完整的 Re4 簇（β-GB）；和那些有破损 Re4 簇（γ-GBs）的。α-GB 的完整构型使它们易于形成，并且它们具有从原始 ReSe ₂继承的半导体特性单层。有趣的是，β-GBs 和γ-GBs 的引入导致局部磁矩的出现，产生于边界周围的Re 5 d _xz原子轨道。此外，具有断裂 Re-Re 键（β-和γ-GBs）的 GBs 在自旋极化的带隙状态中表现出细微的差异，表明电子特性对 GBs 精确原子结构的强烈依赖性。这些结果对于理解二维材料中的低对称性 TMD 和结构-性质关系具有根本重要性。

更新日期：2021-10-04

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11