Proposed growth mechanism of single-walled carbon nanotubes

Open-ended single-wall carbon nanotubes are investigated at finite temperature using an empirical potential and molecular dynamics simulations. These tubes are observed to flare open at their ends due to the change in the local environment at their boundaries. Total energy calculations reveal that this tendency constitutes a potential barrier to tube closure and that the magnitude of the barrier depends on the tube radius. It is argued that this barrier will set an upper limit on the temperature at which tubes of a given radius can form.