a1 Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, The Australian National University, Canberra, ACT 0200, Australia
a2 Electron Microscopy Unit, College of Sciences and Technology, The University of Sydney, NSW 2006, Australia
A high quantity and yield (up to 85%) of boron nitride (BN) nanotubes have been produced using a mechanothermal method. Elemental boron powders were first mechanically milled at room temperature in NH3 atmosphere and subsequently heated in N2 gas at 1200 °C for up to 16 h. The BN nanotubes obtained have either multiwalled cylindrical or bamboolike structures, suggesting different growth processes. The high formation yield of BN nanotubes is due to a high density of nanostructured nuclei created by an extensive milling treatment.
(Received March 13 2002)
(Accepted June 04 2002)