Diamond single crystal

Abstract

An artificial diamond single crystal, at least a part of a surface of the crystal having a rough surface which diffusibly reflects light which is formed by suppressing crystal growth at that surface, and wherein said diamond single crystal is obtained by: providing a diamond synthesis reaction system comprised of a reaction chamber housing having positioned therein a carbon source and a solvent metal arranged in contact with the said carbon source, said reaction system being arranged in a pressure medium; providing a seed crystal in the reaction chamber; providing temperatures of from about 1300.degree. to 1600.degree. C. and pressure of from about 50 to 60 Kb in the reaction chamber which permit diamond to be maintained thermodynamically stable in the reaction chamber housing; heating the reaction chamber to provide a temperature gradient in such a way that a portion of the solvent metal in contact with the carbon source is higher in temperature than a portion of the solvent metal in contact with the seed crystal so as to migrate the carbon from the higher temperature portion to the lower temperature portion using the solvent metal as a medium; and allowing the carbon to precipitate and grow as a diamond on the seed crystal due to the difference in solubility caused by the temperature gradient in the reaction chamber housing; the crystal growth being maintained for about 10 to 100 hours until the crystal growth in the reaction chamber housing in at least one direction perpendicular to the direction of the temperature gradient reaches the contact surface of the solvent metal with the pressure medium having an irregular rough surface and thereby the crystal growth is suppressed at the surface of the pressure medium to thereby form an irregular rough surface on the crystal.

Dependencies are inferred from the claim text.