Synthesis and structural peculiarities of nonstoichiometric β-SiC

摘要

Silicon carbide powder was obtained by reacting silicon and natural graphite particles using self-propagating high-temperature synthesis (SHS). The synthesized powder was investigated by X-ray diffractometry (XRD) and Raman spectroscopy. Decreased lattice parameter of the cubic silicon carbide (β-SiC) (a= 4.353 A) and its crystal structure imperfections were established. Carbon peaks corresponding to a diamond-like structure (1332, 1336 and 1484 cm{sup}-1) were observed in synthesized SiC powder.A defect-free structure of the synthesized β-SiC was obtained after sintering under high pressure and temperature. On the basis of structural calculations it is shown that in the lattice of the synthesized β-SiC, a portion of silicon atoms aresubstituted by carbon atoms.