title: Selective diameter control of single-walled carbon nanotubes in the gas-phase synthesis.
abstract: A novel approach for selective diameter control of single-walled carbon nanotubes (SWNTs) is performed in the gas-phase growth using two kinds of carbon sources with different decomposition properties; the one carbon source (1st carbon source) is the organic solvent which is difficult to decompose in the reactor and the another carbon source (2nd carbon source) is facile to decompose. The diameter distributions of SWNTs synthesized with various conditions of the flow rate of the 2nd carbon source were investigated by resonant Raman scattering, optical absorption, and photoluminescence (PL) mapping measurements. It was found that increasing the flow rate of the ethylene tends to decrease the diameter of synthesized SWNTs, probably due to the earlier nucleation of SWNTs induced by the ethylene addition. The controlling the flow rate of the ethylene used as a 2nd carbon source can selectively tune the diameter distribution of SWNTs in our growth system.
authors.affiliation: Research Center for Advanced Carbon Materials, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi Tsukuba, Ibaraki, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Saito
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ohshima
authors.forename: Toshiya
authors.initials: T
authors.lastname: Okazaki
authors.forename: Shigekazu
authors.initials: S
authors.lastname: Ohmori
authors.forename: Motoo
authors.initials: M
authors.lastname: Yumura
authors.forename: Sumio
authors.initials: S
authors.lastname: Iijima
mesh_terms: D003460:Crystallization / Q000379:methods*; D005740:Gases / Q000737:chemistry; 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; D044367:Phase Transition; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D005740:Gases; D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; C009495:titanium dioxide; D014025:Titanium