Electron irradiation experiments in a transmission electron microscope were combined with kinetic Monte Carlo simulations in order to determine the mobility of interstitial carbon atoms in single-walled carbon nanotubes. The irradiation dose which was necessary to cut nanotubes repeatedly with a focused electron beam was measured as a function of the separation between the cuts and at various temperatures. As the cutting speed was related to the migration of displaced carbon atoms trapped inside the tube and to their recombination with vacancies, information was obtained concerning the mobility of the trapped atoms and their migration barrier was estimated to be about 0.25eV. This was an experimental confirmation of the remarkably high mobility of interstitial atoms inside carbon nanotubes, which showed that nanotubes have potential applications as pipelines for the transport of carbon atoms

The Diffusion of Carbon Atoms inside Carbon Nanotubes. Yanjie, G., Kotakoski, J., Krasheninnikov, A.V., Nordlund, K., Banhart, F.: New Journal of Physics, 2008, 10[2], 023022