title: Chiral-angle distribution for separated single-walled carbon nanotubes.
abstract: Chiral indices (n, m) of metallic and semiconducting single-walled carbon nanotubes (SWNTs) selectively separated via the density-gradient ultracentrifugation process were individually assigned by using an aberration-corrected transmission electron microscope (TEM) operated at 80 kV. Our statistical analysis revealed that armchair (n, n) and chiral (n, n-3) SWNTs with large chiral angles (>20 degrees) are dominant metallic nanotubes in the separated samples, whereas such a noticeable preference of particular indices was not observed for semiconducting nanotubes. Some significant discrepancies were found between the TEM and spectroscopic results on the major chiral indices and the metal/semiconductor ratios in these SWNTs.
authors: Nanotube Research Center, National Institute of Advanced Industrial Science and Technology, and JST-CREST, Tsukuba 305-8565, Japan. yuta-sato@aist.go.jp
authors: Yuta
authors: Y
authors: Sato
authors: Kazuhiro
authors: K
authors: Yanagi
authors: Yasumitsu
authors: Y
authors: Miyata
authors: Kazu
authors: K
authors: Suenaga
authors: Hiromichi
authors: H
authors: Kataura
authors: Sumio
authors: S
authors: Iijima
mesh_terms: D002499:Centrifugation, Density Gradient; D004581:Electronics / Q000379:methods*; D004867:Equipment Design; D053768:Metal Nanoparticles / Q000737:chemistry; D008670:Metals; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*
chemical_list: D008670:Metals; D037742:Nanotubes, Carbon