Single-walled carbon nanotube formation with double laser vaporization technique
Department of Chemistry, Tokyo Metropolitan University,
Hachioji, Tokyo 192-0397, Japan
2 Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
Published online: 3 July 2003
Single-walled carbon nanotubes (SWNTs) were prepared with double laser vaporization of a graphite target and a metal/alloy target inside an electric furnace at 1200 C ambient temperature with 500 torr Ar gas atmosphere. Each target was vaporized simultaneously with a different Nd:YAG laser. Several kinds of metal/alloy target (Ni, Co, Fe, and permalloy) were tested in order to see the difference in the resulting SWNT yield and the diameter distribution of them. The Raman spectra of SWNT-containing soot prepared by use of this technique with permalloy/carbon system indicated that permalloy gives almost the same yield as compared with Ni/Co carbon composite rod with single laser vaporization technique, though the diameter distribution of them is slightly different. Also, time-resolved images of the plume by carbon and permalloy nanoparticles after laser vaporization were collected using a high-speed video camera. These images suggest that the hot plumes due to carbon and permalloy nanoparticles do not mix together so extensively, at least in a few hundred microseconds after laser vaporization. The effect of time delay between two laser pulses on the yield and the diameter distribution of SWNTs was also presented and discussed.
PACS: 36.40.-c – Atomic and molecular clusters / 81.05.Tp – Fullerenes and related materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003