Plasticity of carbon nanotubes: Aiming at their use in nanosized devices

Abstract

Theoretical and experimental works on the plasticity of carbon nanotubes are reviewed in this paper. Theoretical calculations have clarified that plastic elongation and plastic-bend formation occur only at an appropriate high temperature above the critical tensile strain and the critical curvature for straight nanotubes and elastically bent nanotubes, respectively. The initiation of these processes is 5-7-7-5 defect nucleation, then two 5-7 pairs separate from the defect. The pairs glide away to leave a thinner nanotube with a different chirality for the elongation, and glide from the "belly" position for zigzag tubes and from the back position for armchair tubes toward a position close to the neutral plane of the bent tube for the plastic bend. Current-induced experiments have demonstrated that the plastic-bend formation of nanotubes and their recovery are consistent with the theoretical findings. The onset current is rather low and has strong tube-diameter dependence for plastic-bend formation but is extremely high (close to the sublimation curret) for its recovery. ©2007 The Japan Society of Applied Physics.