Fast scooter motion of transition metal in single-wall carbon nanotube growth

We investigate a role of transition metal at the edge of single-wall carbon nanotubes. The potential profile of a metal atom at the edge is evaluated by density functional theory within local density approximation. We estimate transition rate of Ni atom moving around the tube edge using a simple transition state theory to be much faster than that of carbon atom by a factor of 10⁵. This fast Ni motion plays an important role in catalyzing the continuing assembly of hexagons at armchair tube edge.