ANNEALING OF MONOCRYSTALLINE DIAMONDS OBTAINED BY CHEMICAL DEPOSITION FROM GASEOUS PHASE Russian patent published in 2008 - IPC C23C16/27 C30B23/08 

FIELD: inorganic chemistry.

SUBSTANCE: invention relates to the annealing of diamonds, in particular, to monocrystalline CVD diamonds. The method involves increasing temperature of the CVD diamond to the annealing temperature, which is about 1500°C, at a minimum pressure of 4.0 hPa, within the range of the stable phase of graphite or just within the limits of the stable phase of diamond. In rare occasions, after the CVD diamond reaches the annealing temperature, the temperature of the monocrystalline CVD diamond is decreased to the ambient temperature while maintaining the pressure on the monocrystalline CVD diamond. Before annealing, the initial stage of growing of the monocrystalline brown diamond may be conducted, at a temperature of approximately 1400-1460°C, in an atmosphere containing 4-5% N₂/CH₄. A clarified or colourless monocrystalline diamond with enhanced optical properties and no defects is obtained.

EFFECT: clarified or colourless monocrystalline diamond with enhanced optical properties is produced using method of chemical deposition from gaseous phase.

9 cl, 2 dwg, 5 ex

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