Analytical TEM investigations on boron carbonitride nanotubes grown via chemical vapour deposition

A systematic microstructure investigation on the boron carbonitride (BCN) nanotubes, synthesized by bias-assisted hot-filament chemical vapour deposition, is reported. The BCN nanotubes were found to be well-crystallized with uniform diameters and transverse connections inside. Their lengths can be over a few tens of micrometres. Transmission electron microscopy (TEM) analyses indicate that the BCN nanotubes have near zigzag graphic-layered structures with helical angles of less than 30◦. Spatial-resolved electron energy loss spectroscopy (EELS) demonstrates typical sp2 bonding configuration of the nanotubes with pronounced characteristic π∗ and σ∗ peaks of boron and carbon and characteristic K-shell ionization edges of nitrogen. EELS and energy-filtered TEM analyses reveal that the inner layer of the nanotube contains mass of carbon and some amount of boron, and the outer layer and the connections across the inner walls are rich in boron. The nitrogen is found distributing in the nanotube dispersedly and traceable amount of oxygen is measured existing in the shell of the nanotube. New Journal of Physics 6 (2004) 78 PII: S1367-2630(04)79599-3 1367-2630/04/010078+11$30.00 © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft 2 DEUTSCHE PHYSIKALISCHE GESELLSCHAFT