DISTRIBUTION OF PENTAGONS AND SHAPES IN CARBON NANOTUBES AND NANOPARTICLES

The way pentagons are distributed on a closed surface consisting of hexagons and pentagons determines the surface topology. Here, we present high-resolution electron microscopy images of carbon nano-tubes and nano-particles, and show the symmetric and asymmetric distribution of pentagons at their end surfaces. From many observed morphologies it is concluded that no preferred distribution, leading to energetically favorable shapes, exists for the tip ends. It is also seen that the arrangements of pentagons show signatures for helicity in the hexagonal network of carbon on the tube surfaces.