SYNTHESIS OF GRANULAR DIAMOND

摘要

PURPOSE:To produce granular diamond in good productivity and inexpensively in gas phase synthesis of granular diamond using plasma, by dispersing and floating base material particles in a mixed gas of an organic compound and hydrogen having a specific velocity and providing part having space concentration of particles in a given range with electric field. CONSTITUTION:A quartz pipe 1 is charged with base material particles 6 and as the quartz pipe is evacuated by a vacuum pump 4, a mixed gas of an organic compound (e.g., methane) and hydrogen is introduced from the bottom of the quartz pipe 1 at a flow velocity so as to make partially jump out the base material particles 6 from the quartz pipe 1 and the material particles 6 are dispersed and floated. The base material particles 6 jumping out are recovered by a cyclone 3 and recycled in the quartz pipe 1. Then part of the base material particles 6 having >=20vol% to >=1vol% space concentration is provided with an electric field of AC or DC current, the mixed gas is made into plasma and diamond is precipitated on the dispersed and floated base material particles 6.