Single-walled BN nanostructures

The in situ synthesis of single-walled BN nanotubes terminated by fullerene-like structures was studied using electron-cyclotron resonance nitrogen and electron beam boron sources onto polycrystalline tungsten substrates. High resolution electron microscopy images and simulations based upon molecular models revealed a dominance of kinks and bends having a fourfold and eightfold ring structures as against fivefold or sevenfold found with carbon. The structures are growing by adding atoms to the exposed ends of single sheets, not at the substrate-nanostructure interface.