METHOD FOR OBTAINING DOPED DIAMOND MONOCRYSTAL Russian patent published in 2018 - IPC B01J3/06 C30B31/02 C30B29/04 C01B32/26 C01B31/06 

FIELD: chemistry.

SUBSTANCE: method of growing diamond single-crystals doped with nitrogen and phosphorus at high pressures of 5.5-6.0 GPa and temperatures of 1600-1750°C is carried out on the seed crystal, which is pre-pressed into a substrate of cesium chloride and separated from the source of carbon, nitrogen, and phosphorus with the metal-solvent, which is used as an alloy of iron, aluminium, and carbon. Between the source of carbon, nitrogen, and phosphorus and the seed crystal, a temperature difference of 20-50°C is created. The alloy of iron, aluminium, and carbon in the metal-solvent is taken with the following component ratio, wt %: iron 92.5-95.0; aluminium 2.5-0.5; carbon 5.0-4.0. The mixture of the source of carbon, nitrogen, and phosphorus is taken with the following component ratio, wt %: carbon (graphite) 95.0-97.0; phosphorus 5.0-3.0; adsorbed nitrogen 0.001±0.0005. Heating is carried out up to the initial temperature in a zone of growth at 100-250°C higher the melting temperature of the alloy of the metal-solvent, the exposure is produced at this temperature for 50 to 150 h. The mass flow rate of crystal growth is more than 2 mg/h. The technical result consists in the controlled doping the diamond single- crystal grown on the seed with impurities of phosphorus and nitrogen in the conditions of influence of high pressure and temperature.

EFFECT: resulting large diamond single-crystals contain a nitrogen admixture in the concentration of 0,1-17,8 parts per million of carbon atoms and phosphorus in a concentration of 0,5-5 parts per million of carbon atoms.

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