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Title: Structurally inhomogeneous nanoparticulate catalysts in cobalt-catalyzed carbon nanotube growth

The structure of nanoparticulate catalysts involved in cobalt-catalyzed chemical vapor deposition growth of carbon nanotubes (CNTs) was investigated by in situ environmental transmission electron microscopy (ETEM). In contrast to previous studies, the analyses of ETEM images showed that the nanoparticulate catalysts were structurally inhomogeneous during CNT growth in the source gas of acetylene at a rate of pressure increase of about 3 Pa/h and at 550 °C. The lattice fringes observed in the nanoparticulate catalysts can be accounted for by not a single crystalline structure but by several possible pairs of structures including pure Co and cobalt carbides. The inhomogeneous structures were unstable with time. The possible origin of the inhomogeneous structures is discussed.
Authors:
 [1] ;  [2] ; ;  [1] ;  [3]
  1. The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)
  2. (Japan)
  3. Department of Physics, Tokyo University of Science, Shinjuku, Tokyo 162-8601 (Japan)
Publication Date:
OSTI Identifier:
22310907
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; CARBON NANOTUBES; CATALYSTS; CHEMICAL VAPOR DEPOSITION; COBALT; COBALT CARBIDES; CRYSTAL GROWTH; MONOCRYSTALS; TEMPERATURE RANGE 0400-1000 K; TRANSMISSION ELECTRON MICROSCOPY