title: Smallest carbon nanotube assigned with atomic resolution accuracy.
abstract: The smallest carbon nanotubes with the chiral index (3,3), (4,3), or (5,1) were unambiguously identified for the first time. They were grown inside single-wall carbon nanotubes with the diameter of 1.0-1.2 nm, and the chiral indices were experimentally assigned beyond a doubt by an aberration-corrected high-resolution transmission electron microscopy (HR-TEM). In contrast to a theoretical prediction, the (3,3) nanotube is rather unstable and extremely sensitive to the electron beam and, therefore, may not survive alone without the protection of outer nanotube. The cap structure of (3,3) nanotube is also well-explained by a half-dome of C20 fullerene, which consists of six pentagons only.
authors.affiliation: Research Center for Advanced Carbon Materials, National Institute of Advanced Industrial Science and Technology Tsukuba, 305-8565, Japan. guan-lunhui@aist.go.jp
authors.forename: Lunhui
authors.initials: L
authors.lastname: Guan
authors.forename: Kazu
authors.initials: K
authors.lastname: Suenaga
authors.forename: Sumio
authors.initials: S
authors.lastname: Iijima
mesh_terms: D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon