Field-induced unraveling of carbon nanotubes

We investigate the disintegration mechanism of carbon nanotubes in strong electric fields using the ab initio density functional formalism. We find that nanotubes withstand fields up to 2 V/Angstrom before they start unraveling carbon chains from the exposed edge, followed by field-induced fragmentation. We find this unraveling to be facilitated in negatively charged tubes, which have been shown to be efficient nano-scale electron emitters. We demonstrate that unraveling terminates at sites where adjacent walls are bridged by a covalent bond. (C) 1997 Published by Elsevier Science B.V.