Synthesis of β-SiC nanowires with SiO2 wrappers

beta-SiC nanowires with uniform amorphous SiO2 wrappers have been synthesized by carbothermal reduction of the sol-gel derived silica containing carbon nanoparticles. The product was characterized by IR, TEM, HREM, and EDX. The nanostructures are more than 20 mu m in length. The diameters of beta-SiC nanowires are in the range 10 similar to 25 nm, while the outer diameters of the SiO2 wrappers are between 20 and 70 nm. The formation of beta-SiC nanowires is ascribed to the large quantities of SiC nuclei and the nanometer-sized SiC nucleus sites on carbon nanoparticles. The SiO2 wrappers come from the combination reaction of the SiO vapor and O-2 decomposed from the unreacted SiO2. (C) 1999 Acta Metallurgica Inc.