PREPARATION OF SILICON-CARBIDE POWDERS BY CHEMICAL VAPOR-DEPOSITION OF THE (CH3)2SICL2-H2 SYSTEM

Silicon carbide (SiC) powders were prepared by chemical vapour deposition (CVD) using (CH3)2SiCl2 and H2 as source gases at temperatures of 1273 to 1673 K. Various kinds of SiC powders such as amorphous powder, β-type single-phase powder and composite powder were obtained. The composite powders contained free silicon and/or free carbon phases of about a few nanometres in diameter. All the particles observed were spherical in shape and uniform in size. The particle size increased from 45 to 130 nm with decreasing reaction temperature and gas flow rate, as well as with increasing reactant concentration. The lattice parameter of the β-SiC particles decreased with increasing reaction temperature. All the lattice parameters were larger than those of bulk β-SiC. © 1990 Chapman and Hall Ltd.