| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2001: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2000: ¥1,900,000 (Direct Cost: ¥1,900,000)
|
|---|
| Research Abstract |
It is important to investigate the role of carbon and metal nanoparticles in the formation process of fullerenes and single-walled carbon nanotubes. Experimantal findings obtained in this project by use of a laser furnace apparatus combind with a high-speed video camera are in the following.
1) It is clarified that the time scale of the main formation process of fullerenes is ca. 1 msec. Also, in addition to the increase in the blackbody emission intensity, the formation of C_2 in the same time domain was found. Based on these experimental findings, a model for the formation of fullerenes was proposed, where firstly, small-sized carbon clusters are combined to grow, secondly cooled down by blackbody emission and C_2 elimination, and finally take a form of round structure.
2) The formation of single-walled carbon nanotubes under different kinds of ambient gas, gas pressure, and gas velocity in the formation field was extensively investigated. The results show that, though the yield of single-walled carbon nanotubes does not depend so much on the kind of ambient rare gas such as Ne, Ar and Kr, nitrogen gas (N_2) gives the highest yield for single-walled carbon nanotube formation. Additionally, it was found that single-walled carbon nanotubes could be generated by mixing metal nanoparticles with carbon nanoparticles after laser vaporization. This indicates that metal nanoparticles contribute to the growth process of single-walled carbon nanotubes, ca. 1 msec after laser vaporization.
|
