SYNTHESIS OF NANOMETER-SIZED SIC POWDERS THROUGH CHEMICAL-VAPOR-DEPOSITION II - EFFECT OF C2H4 SIH4 MOLE RATIO/

In this paper, the effect of the C2H4/SiH4 mole ratio on the particle size, composition and stoichiometry of nanometer-sized SiC powders has been explored. It is revealed that particle size is a strong function of the C2H4/SiH4 mole ratio and powders having an average size as sma ll as 13 nm are obtained when the parameter is selected to be 1.2, for which the underlying mechanism has been elucidated. Furthermore, it i s found that C2H4/SiH4 mole ratio also exerts a crucial effect upon th e composition and stoichiometry of product powders. By optimizing some pertinent parameters such as temperature and C2H4/SiH4 mole ratio, th e chemical reactions responsible for the synthesis of SiC powders coul d be coordinated and the impurities within the powders were thus minim ized. (C) 1998 Elsevier Science S.A. All rights reserved.