REDUCED-PRESSURE CHEMICAL-VAPOR SYNTHESIS OF NANOCRYSTALLINE SILICON-CARBIDE POWDERS

Nanocrystalline beta-SiC powders with grain and particle sizes well be low 10 nm are prepared by thermal decomposition of silicon organic pre cursors under reduced pressure conditions. This modified CVD process i s called chemical vapor synthesis (CVS). The influence of synthesis pa rameters on powder characteristics is investigated. Small grain and pa rticle sizes together with low agglomeration and high crystallinity ar e achieved for tetramethylsilane as precursor, total pressures below o r equal to 1000 kPa, reaction temperatures above 1400 K, and precursor partial pressures below or equal to 660 Pa.