Preparation and characterization of single-phase SiC nanotubes and C-SiC coaxial nanotubes

Preparation conditions of single-phase SiC nanotubes and C-SiC coaxial nanotubes were investigated. The characterization of single-phase SiC nanotubes and C-SiC coaxial nanotubes were carried out. The SiC nanowires, which were made of the catenated SiC grains of 50-200 nm in diameter, were obtained in carbon nanotubes reacted at 1450 degrees C. The only C-SiC coaxial nanotubes were formed at 1300 degrees C. A few single-phase SiC nantoubes were synthesized at 1200 degrees C for 100 h. More than half number of nanotubes reacted at 1200 degrees C for 100 h were altered to single-phase SiC nantoubes by heat treatment of 600 degrees C for 1 h in air since the remained carbon was removed. The energy dispersive X-ray spectroscopy analysis revealed that the atomic ratio of Si to C in single-phase SiC nanotubes was almost 1; these single-phase SiC nanotubes consisted of near-stoichiometric SiC grains. (c) 2005 Elsevier B.V. All rights reserved.