SURFACE MICROSTRUCTURES OF DIAMOND CRYSTALS SYNTHESIZED IN THE H2-CH4-O2 SYSTEM

The dependence of the microstructures of the {111} surfaces of diamond crystals synthesized in the H2-CH4-O2 system on the oxygen-carbon ratio (O/C) has been studied to elucidate the mechanism of the crystal growth. On the {111} surfaces of diamond crystals synthesized in high O/C (greater-than-or-equal-to 0.8, in our synthesized conditions), the two-dimensional nucleation rate is suppressed and the two-dimensional crystal growth rate is promoted. The Raman spectrum of the diamond crystals synthesized in high O/C shows that the half width at half maximum and the peak position are equivalent to those of natural diamond crystals.