Metal particle catalysed production of nanoscale BN structures

Graphite-like nanostructures including nanotubes and encapsulated polyhedral particles have been obtained by arcing hexagonal boron nitride (h-BN) and tantalum in a nitrogen atmosphere. High resolution electron microscopy (HRTEM), electron energy loss spectroscopy (EELS) and X-ray diffraction studies have been used to study these new materials, which contain B:N ratios of approximate to 1:1. The observations reveal interesting new information on the dynamics of metal cluster catalysed nanostructure formation. The structures provide strong circumstantial evidence for the presence of B2N2 squares at the tips, in addition to B3N3 hexagons in the main body of the tubes.