THERMODYNAMICS FOR THE PREPARATION OF SIC-C NANO-COMPOSITES BY CHEMICAL VAPOR-DEPOSITION

SiC-C nano-composites covering every possible combination of carbon and SiC were prepared by chemical vapour deposition. The specific compositions of the deposits were controlled by changing the Si/C molar ratio in the source gases at deposition temperatures (Tdep) of 1673 to 1873 K and total gas pressures (Ptot) of 6.7 to 40 k Pa using the SiCl4-C3H8-H2 system. The prediction, based on the thermodynamic calculation on composition, morphology and deposition rate, was compared with experimental results. The optimal deposition conditions predicted by the calculations were nearly in agreement with the experimental results. © 1990 Chapman and Hall Ltd.