AVS 49th International Symposium
    Plasma Science Tuesday Sessions
       Session PS-TuP

Paper PS-TuP23
LIF Measurement of Catalytic Species in Plasma Plume for Carbon Nanotubes Formation by PLA

Tuesday, November 5, 2002, 5:30 pm, Room Exhibit Hall B2

Session: Plasma Applications
Presenter: T. Ikegami, Kumamoto University, Japan
Authors: T. Ikegami, Kumamoto University, Japan
M. Uchiyama, Kumamoto University, Japan
K. Ebihara, Kumamoto University, Japan
J. Asmussen, Michigan State University
Correspondent: Click to Email
Single wall carbon nanotubes (SWNT) have been synthesized in an inert gas, 500 Torr, atmosphere by using pulsed laser ablation (PLA) on a graphite target containing metal catalysts such as Fe, Ni/Co. In order to clarify the mechanism of formation of carbon clusters and to understand the role of catalytic atoms in the formation of SWNT, carefully diagnostic experiments have been conducted. Specifically a carbon and Fe or Ni composite target was ablated by KrF excimer laser or YAG laser in Ar gas environment of several hundred Torr. Carbon species such as atoms, ions and molecules C@sub 2@ and C@sub 3@ in the ablation plasma plume were measured using absorption spectroscopy, ion probe, laser induced fluorescence (LIF) method, respectively. At the same time density profiles of catalytic Fe and Ni atoms were also measured using LIF method. By changing laser fluence on the target and laser wavelength (@lambda@=248nm, 532nm, 1064nm), the relationship between carbon species and catalytic species profiles was investigated. Also the effect of magnetic and electric fields on these species was examined. Nanoparticulate soot was collected and refined to obtain nanotubes after the ablation. Properties of nanotubes were measured using AFM, XRD, FT-IR, XPS and ESR. Preliminary measurements on carbon species indicate that their density and profiles are strongly affected by laser wavelength and fluence. Species concentrations vs. the type of the catalyst will be also discussed. This research is partly supported financially by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (C), Japan.