Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan.
Nat Commun. 2011;2:213. doi: 10.1038/ncomms1224.
Edge structures and atomic defects can significantly affect the physical and chemical properties of low-dimensional materials, such as nanoribbons, and therefore merit a thorough investigation at the atomic scale. Here, we successfully discriminate single atoms on a monolayered tungsten disulphide nanoribbon by means of time-resolved annular dark-field imaging and spatially resolved electron energy-loss spectroscopy. We unambiguously identify and successfully visualize in motion atomic defects, such as vacancies and edge atoms, using scanning transmission electron microscopy. We also report a direct observation of slip deformation in the nanoribbons and present evidence demonstrating that the deformation process involves the migration of vacancies and rearrangement of tungsten atoms. Single-atom defects are successfully observed for the first time during plastic deformation.
边缘结构和原子缺陷会显著影响低维材料（如纳米带）的物理和化学性质，因此需要在原子尺度上进行深入研究。在这里，我们通过时间分辨环形暗场成像和空间分辨电子能量损失谱成功地分辨出单层二硫化钨纳米带中的单个原子。我们使用扫描透射电子显微镜明确识别并成功可视化了原子缺陷（如空位和边缘原子）的运动。我们还报告了在纳米带中直接观察到的滑移变形，并提供了证据表明变形过程涉及空位的迁移和钨原子的重新排列。在塑性变形过程中，首次成功观察到了单个原子缺陷。
