A single crystal of cubic boron nitride (cBN) was grown under the high-pressure and high-temperature conditions of 5. 5 GPa and 1500-1700 for 10min. -100 h. A temperature gradient method was employed for the crystal growth by using lithium boron nitride as a solvent. In order to characterize the growth features of cBN single crystal on seed surfaces, large seeds of diamond crystals were employed, and the heteroepitaxial growth of cBN on (100) and (111) diamond surfaces was studied. The initialgrowth feature of the cBN crystal was found on the diamond seed surface after a growing time of 10 min. On the (100) seed surface, typical anti-phase boundaries were exhibited in the grown crystals, while they were not seen in crystals grown on a (111) surface. Two types of growth features such as (111) and (113) facetted growth typically appeared in the grown crystal on the (111) surface. Considering the growth process under a constant P-T growing condition, the growth rate of cBN crystal was significantly small as compared to that of diamond.
