Selective synthesis of zigzag-type aligned carbon nanotubes on SiC (0 0 0 −1) wafers

Zigzag-type carbon nanotubes have been selectively produced by surface decomposition of a well-polished SiC single crystal. The SiC wafer was heated to 1500 °C at a very small heating rate under vacuum. Transmission electron microscopy (TEM) and electron diffraction patterns revealed that almost all the well-aligned carbon nanotubes formed perpendicular to the SiC (0 0 0 −1) surface were double-walled and of zigzag type. The results of high-resolution electron microscopy (HREM) indicate that the zigzag type structure evolves from the Si–C hexagonal networks in the SiC crystal by the collapse of carbon layers remaining after the process of decomposition.