SURFACE RECONSTRUCTIONS AND DIMENSIONAL CHANGES IN SINGLE-WALLED CARBON NANOTUBES

Dimensional stability is crucial to possible applications of single-wa lled nanotubes, as their properties are linked to size and topology. W e observe nanotubes responding to uniform atom loss, through surface r econstruction and drastic dimensional changes. Experiments using elect ron irradiation evidence nanotube diameters shrinking from similar to 1.4 to 0.4 nm. Molecular dynamics simulations show that surface recons truction and size reduction occur through dangling bond saturation, fo rming nonhexagonal rings and 5-7 defects in the lattice. Nonuniform at om removal results in inhomogeneous tube deformations and local neckin g, and formation of linear atomic carbon chains in the nanotube body.