标题： 超导Sn插层TaSe$_2$：传统表征技术掩盖的结构多样性 显示英文标题

标题： Superconducting Sn-Intercalated TaSe$_2$: Structural Diversity Obscured by Conventional Characterization Techniques

摘要： 以Sn插层的TaSe$_2$作为模型系统，我们通过单晶X射线衍射揭示了结构异质性，而这种异质性逃避了常见的表征技术（如粉末X射线衍射、拉曼光谱和电输运测量）。 从单一生长成分（Sn:Ta:Se = 1:1:2）中，我们获得了多种化学计量比和结构，对于Sn$_x$TaSe$_2$从 $0\leq\textrm{x}\leq1$的连续插层。 利用单晶X射线衍射，我们确定了四种新结构： Sn$_{0.18}$TaSe$_{1.92}$ ($R3m$)，Sn$_{0.37}$TaSe$_{2.14}$ ($R\bar3$)， Sn$_{0.42}$TaSe$_{2.04}$ ($P\bar31c$)，以及 Sn$_{1.1}$TaSe$_2$ ($Fmm2$)。 相比之下，粉末X射线衍射无法解析所有四种结构。拉曼光谱在标准测量范围内无法区分不同的结构或组成。输运测量显示，无论锡插层的量是多少或者电荷密度波行为是否出现，都表现出一致的超导性。本工作强调了普通方法在捕捉插层过渡金属二硫属化物结构多样性方面的敏感度不足，并指出在研究范德瓦尔斯层状化合物性质时需要高分辨率的结构表征。 显示英文摘要

摘要： Using Sn-intercalated TaSe$_2$ as a model system, we uncover structural heterogeneity by single-crystal X-ray diffraction that eludes the common characterization techniques of powder X-ray diffraction, Raman spectroscopy, and electrical transport measurements. From a single growth composition (1:1:2 Sn:Ta:Se), we obtain diverse stoichiometries and structures, with near-continuous intercalation for Sn$_x$TaSe$_2$ from $0\leq\textrm{x}\leq1$. Using single-crystal X-ray diffraction, we identify four new structures: Sn$_{0.18}$TaSe$_{1.92}$ ($R3m$), Sn$_{0.37}$TaSe$_{2.14}$ ($R\bar3$), Sn$_{0.42}$TaSe$_{2.04}$ ($P\bar31c$), and Sn$_{1.1}$TaSe$_2$ ($Fmm2$). In contrast, powder X-ray diffraction cannot resolve all four structures. Raman spectroscopy is unable to distinguish different structures or compositions in the standard measurement range. Transport measurements show consistent superconductivity irrespective of Sn-intercalation amount or appearance of charge density wave behavior. This work underscores the inadequate sensitivity of common approaches in capturing the structural diversity of intercalated transition metal dichalcogenides and the need for high-resolution structural characterization when examining the properties of van der Waals-layered compounds.