We have studied the effect of strain on the electronic properties of multiwall carbon nanotubes using scanning tunneling microscopy and spectroscopy. While small elastic strain causes no change of the electronic properties of the nanotubes, tubes under large strain by lying over an inter-grain boundary of the Au substrate show drastic electronic heterogeneity. The observed variation in local electronic property is explained in terms of the mechanical relaxation of the outer most layer of the tube. This provides first evidence of the effect of mechanical modification on local electronic structure of a carbon nanotube.

• Received 2 January 2001

DOI:https://doi.org/10.1103/PhysRevB.64.035419