Synthesis of nanocrystalline silicon carbide using the sol-gel technique

Highly disperse silicon carbide is synthesized using a hybrid method comprising the sol-gel step to provide the SiO₂-C starting mixture involving the formation of a transparent gel and carbothermal synthesis under relatively soft conditions, namely, at temperatures of 1200–1500°C under a dynamic vacuum. The elemental and phase compositions of the products and their thermal behavior in air are studied. A relationship is found to exist between the microstructure of the product, on the one hand, and the temperature and time of heat treatment, on the other.