2003 年 30 巻 4 号 p. 285-290
Various metal catalysts are used to synthesize single-wall and double-wall carbon nanotubes by arc discharge method. Metals used commonly as catalysts are classified into the iron-group, the platinum-group and the rare-earth elements. The catalytic activities are greatly enhanced by combining two (or more) metals for certain combinations. Effects of catalysts on the structure and the yield of carbon nanotubes are first reviewed. Then, recent findings on field emission of electrons from carbon nanotubes are presented. Field emission microscopy revealed the preferential emission of electrons from the pentagons on a nanotube tip and the adsorbed molecules. We succeeded in observing atomically resolved five carbon atoms forming a pentagon by field ion microscopy.