Effects of temperature oscillations on the growth of carbon nanotubes by chemical vapor deposition

We have grown carbon nanotubes at oscillatory growth temperature by chemical vapor deposition. The high-resolution transmission electron microscopy (HRTEM) images show that they contain a number of incomplete carbon layers both on the outer and inner periphery and dislocations in the middle part of the carbon nanotubes walls. The defect structure of these nanotubes depends on the period of the T oscillation. In addition, HRTEM examinations of these carbon nanotubes from end-on reveal that some have polyhedral sections and contain dislocations. These features make them more active chemically and might have significant influence on the properties and applications of the carbon nanotubes. (C) 2000 American Institute of Physics. [S0003-6951(00)01007-X].