Jy. Choi et al., SIC ENHANCED NUCLEATION OF DIAMOND UNDER HIGH-PRESSURE AND HIGH-TEMPERATURE, DIAMOND AND RELATED MATERIALS, 5(10), 1996, pp. 1214-1217
Three kinds of catalyst have been prepared to investigate the role of
SIC in diamond nucleation under high pressure and high temperature: (1
) a fresh Ni-SiC powder mixture; (2) a heat-treated Ni-SiC mixture at
1300 degrees C for 2 h in vacuum, and (3) a heat-treated Ni-Si mixture
at 1100 degrees C for 3 h in vacuum. When carbon black was treated wi
th each catalyst at 4.7 GPa, 1450 degrees C for 5 min, diamond was syn
thesized only in the specimen containing the fresh mixture of Ni-SiC c
atalyst. The added fresh SiC enhanced drastically diamond formation. S
iC thus appears to act as direct nucleation sites of diamond under the
experimental condition.