Transition-metal dichalcogenides containing tellurium anions show remarkable charge-lattice modulated structures and prominent interlayer character. Using cryogenic scanning transmission electron microscopy (STEM), we map the atomic-scale structures of the high temperature (HT) and low temperature (LT) modulated phases in $1T^{\prime }\text{−}{\mathrm{TaTe}}_2$. At HT, we directly show in-plane metal distortions which form trimerized clusters and staggered, three-layer stacking. In the LT phase at 93 K, we visualize an additional trimerization of Ta sites and subtle distortions of Te sites by extracting structural information from contrast modulations in plan-view STEM data. Coupled with density functional theory calculations and image simulations, this approach opens the door for atomic-scale visualizations of low temperature phase transitions and complex displacements in a variety of layered systems.

中文翻译：

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1T'-TaTe2中三聚态的直接可视化

含碲阴离子的过渡金属二卤化物显示出显着的电荷-晶格调制结构和突出的层间特征。使用低温扫描透射电子显微镜（STEM），我们绘制了高温（HT）和低温（LT）调制相的原子尺度结构$\mathrm{1个}{Ť}^{\prime }\text{-}{\mathrm{泰特}}_2$。在HT，我们直接显示面内金属变形，这些变形形成三聚簇和交错的三层堆叠。在93 K的LT阶段，我们通过从平面图STEM数据中的对比度调制中提取结构信息，可视化了Ta位点的另外三聚和Te位点的细微扭曲。结合密度泛函理论计算和图像模拟，此方法为各种分层系统中低温相变和复杂位移的原子级可视化打开了大门。