High-resolution electron microscopic studies of the microstructure and specific defects in hexagonal boron nitride precursors and cubic boron nitride crystals, made under high-pressure high-temperature conditions, revealed the presence of half-nanotubes at the edges of the hexagonal boron nitride particles. Their sp3 bonding tendency could strongly influence the nucleation rates of cubic boron nitride. The atomic resolution at extended dislocations was insufficient to permit the determination of stacking-fault energies for the boron nitride crystals. Its mean value of 191mJ/m2 was of the same order of magnitude as that of diamond.

Microstructure and Spectroscopy Studies on Cubic Boron Nitride Synthesized under High-Pressure Conditions. L.C.Nistor, S.V.Nistor, G.Dinca, P.Georgeoni, J.Van Landuyt, C.Manfredotti, E.Vittone: Journal of Physics - Condensed Matter, 2002, 14[44S], 10983-8