Abstract Room temperature (RT) adsorption of tin (Sn) under ultra-high vacuum (UHV) conditions on mechanically cleaved tungsten disulfide (WS2) surfaces is reported here. In-situ low energy electron diffraction (LEED) and scanning tunneling microscopy (STM) studies indicate commensurate adsorption of Sn on the hexagonal surface of WS2. Bare WS2 displays an atomic periodicity of lattice constant 0.34 nm. Growth of Sn reveals monomer like a single atom or unpaired (U) and dimer like- or paired (P) adsorptions on the top (`T’) sulfur (S) sites of the trigonal prismatic sublattice within the honeycomb lattice of WS2. The lateral distance between two nearest adsorbed monomers is around 0.34 nm which is exactly similar to the atomic periodicity of the underneath WS2 substrate crystal. For the case of dimer like- adsorption, the separation between two adspecies is 0.293 nm. The bond length of the adsorbed Sn with the surface S atoms is around 40 (±10) pm. We do not find any evidence of Sn adsorption on the bridge (`B’) or hollow (`H’) site of the WS2 lattice. Analysis of the LEED spots and the FFT images of the STM micrographs after Sn adsorption discloses a stretched hexagonal surface which is most likely due to the overall consequence of a perfectly commensurate monomer and nearly commensurate dimer like- adsorptions of the Sn atoms on the WS2 surface.

中文翻译：

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室温下 Sn 在机械裂解 WS2 表面的原子吸附

摘要 本文报道了在超高真空 (UHV) 条件下在机械裂解的二硫化钨 (WS2) 表面上室温 (RT) 吸附锡 (Sn)。原位低能电子衍射 (LEED) 和扫描隧道显微镜 (STM) 研究表明 WS2 的六边形表面上有相称的 Sn 吸附。裸 WS2 显示晶格常数为 0.34 nm 的原子周期性。Sn 的生长揭示了 WS2 蜂窝状晶格内三角棱柱亚晶格顶部 ('T') 硫 (S) 位点上的单原子或未成对 (U) 和二聚体样或成对 (P) 吸附。两个最近的吸附单体之间的横向距离约为 0.34 nm，这与下方 WS2 衬底晶体的原子周期性完全相似。对于二聚体样吸附的情况，两个adspecies之间的间隔是0.293 nm。吸附的 Sn 与表面 S 原子的键长约为 40 (±10) pm。我们没有在 WS2 晶格的桥（'B'）或空心（'H'）位点上发现任何 Sn 吸附的证据。对 LEED 斑点和 Sn 吸附后 STM 显微照片的 FFT 图像的分析揭示了拉伸的六边形表面，这很可能是由于完全相称的单体和几乎相称的二聚体样 - WS2 表面上的 Sn 原子吸附的总体结果.