Abstract Submitted to the NANOTUBE'02 Workshop:

Extreme toughness and high current- and heat-conductance of carbon nanotubes are promising signs for application to nano-devices. Yet currently provided nanotubes are not ideally perfect, so lifetimes of nano-devices consisting of defective nanotubes will be a practical problem. We here demonstrate stability of a very narrow defective nanotube by performing the tight-binding molecular dynamics (TBMD) simulations [1] and the time-dependent density functional theory molecular dynamics (TDDFT-MD) simulations [2]. We have tested a nanotube with a chiral index of (3,3) having a periodic array of single vacancies. The TBMD simulations suggested survival of this defective nanotube even above 4000⁰ Kelvin, and showed transient dimerization of two of the three C atoms adjacent to the vacancy. On the other hand, the TDDFT-MD simulations showed survival of this nanotube under illumination causing optical excitation among the defect related states. Very athermal ionic motion near the vacancy was induced by the excitation, and the dimerization occurred again. The dimerization observed in both types of simulations is supported by curvature of tubule walls and expected to improve the conductance and stiffness of the defected nanotubes. Thus we would like to call this dimerization as 'self-healing'.

1. S. G. Kim and D. Tomanek, Phys. Rev. Lett. 2418 (1994).
2. O. Sugino and Y. Miyamoto, Phys. Rev. B59, 2579 (1999).