Abstract Submitted to the    NANOTUBE'04 Conference:

The detailed structure-control of single-walled carbon nanotubes (SWNTs) is one of the critical problems for SWNT applications to industrial fields. Especially, though the individual SWNT is an ideal shape for full use of SWNT potential abilities, its production is difficult due to van der Waals attraction effect. In order to overcome this critical problem, we have attempted to realize vertical-alignment control of SWNT using plasma-enhanced chemical vapor deposition (PECVD). Actually, we have recently succeeded for the first time in the SWNT production by PECVD [1]. Owing to intensive high ion-bombardment effects, however, we are confronted by a difficulty in controlling the vertical alignment of SWNTs. Thus, a method of decreasing the ion impact is pursued, where the operation time of PECVD is precisely adjusted. Based on this modified PECVD, it has been found that SWNTs are grown from zeolite with vertical alignment. Furthermore, the detailed transmission electron microscopy observation reveals that only the SWNT with short length forms an individual shape. This result indicates that our method might serve as a promising guide in high-density freestanding SWNT production. We also investigate the plasma effects on the SWNT growth. According to this study, the radical densities of hydrogen and CH appear to have a close relation to the SWNT growth.

[1] T. Kato, et al., Chem. Phys. Lett. 381 (2003) 422.