2003 年 30 巻 4 号 p. 316-321
Well-aligned carbon nanotube (CNT) films were synthesized by surface decomposition of silicon carbide (SiC) (0001). In the initial stage of the decomposition, at 1200-1250℃, the generation of semispherical carbon caps of several nanometers all over the surface of SiC was found by cross-sectional transmission electron microscopy (TEM) and atomic force microscopy (AFM) . The diameter of the grown CNTs is determined initially by that of the nanocaps. Moreover, zigzag-type CNTs are selectively produced by surface decomposition of a well-polished SiC single crystal. The SiC wafer was heated to 1500℃ at a very small heating rate under vacuum. TEM and electron diffraction patterns revealed that almost all the well-aligned CNTs formed perpendicularly to the SiC (0001) surface are double-walled and of zigzag type. In addition, the results of high-resolution electron microscopy (HREM) indicate that the zigzag-type structure evolves from Si-C hexagonal networks in the SiC crystal by the collapse of carbon layers remaining after the process of decomposition.