Atomic structures and formation mechanism of boron nitride nanotubes and nanohorns synthesized by arc-melting LaB6 powders

Boron nitride (BN) nanotubes and nanohorns with various tip structures were synthesized by arc-melting LaB6 powders. Atomic structure models and formation mechanism for BN nanotubes and nanohorns were proposed from high-resolution electron microscopy (HREM), energy dispersive X-ray spectroscopy (EDX), molecular mechanics calculations (MM2) and thermodynamic calculation. The present work indicates that lanthanum would be a key catalytic material to produce the BN nanostructures.