The synthesis of boron nitride nanotubes by an extended vapour-liquid-solid method

An extended vapour-liquid-solid (VLS) growth method, which is the reaction of a mixture of nitrogen and ammonia gas over nanoscale Fe-B 'catalyst' particles at 1100degreesC, has been developed. With this method, BN nanotubes of diameter about 20 nm have been prepared and well characterized by high-resolution transmission electron microscopy and energy dispersive x-ray spectroscopy. In contrast to traditional VLS growth, the boron component in the BN nanotubes comes from the Fe-B 'catalyst' itself, rather than from the vapour precursor. A growing mechanism has been discussed accordingly.