Mechanochemical Synthesis of Boron Nitride Nanotubes

Boron nitride (BN) nanotubes have been produced from elemental boron powder using a new low-temperature process, which involves ball milling of boron powder in ammonia gas at room temperature, and followed by annealing at temperatures up to 1300°C in nitrogen gas. Ball milling induces nitriding reactions between the boron powder and the ammonia gas with the formation of a disordered BN phase. BN nanotubes then grow out during the subsequent heat treatment. This novel process for forming BN nanotubes is distinctly different from arc discharge and laser-heating processes.