title: Identification of active atomic defects in a monolayered tungsten disulphide nanoribbon.
abstract: 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.
authors.affiliation: Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan. liu-z@aist.go.jp
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Kazu
authors.initials: K
authors.lastname: Suenaga
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Wang
authors.forename: Zujin
authors.initials: Z
authors.lastname: Shi
authors.forename: Eiji
authors.initials: E
authors.lastname: Okunishi
authors.forename: Sumio
authors.initials: S
authors.lastname: Iijima