Single-crystal diamond of very high thermal conductivity
AssigneeGeneral Electric Company
InventorsThomas R. Anthony, William F. Banholzer, James F. Fleischer
Life of this patent
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Abstract
Single-crystal diamond consisting of isotopically pure carbon-12 or carbon-13 has been found to have a thermal conductivity higher than that of any substance previously known, typically at least 40% higher than that of naturally occurring IIA diamond. It may be prepared by a method comprising an initial step of low pressure chemical vapor deposition employing an isotopically pure hydrocarbon in combination with hydrogen, followed by comminution of the diamond thus obtained and conversion thereof to single-crystal diamond under high pressure conditions.
Claims23
A method for preparing isotopically pure single-crystal diamond having a thermal conductivity of at least 31.5 watts/cm..degree.K. at 300.degree. K. which comprises the steps of:
- (A) depositing a layer of diamond on a substrate by a chemical vapor deposition method comprising low pressure activation of a mixture of hydrogen and a hydrocarbon consisting of isotopically pure carbon-12 or carbon-13;
- (B) removing and comminuting said diamond layer;
- and
- (C) converting the comminuted diamond to single-crystal diamond by diffusion under high pressure through a metallic catalyst-solvent material to a region containing a diamond seed crystal.
A single-crystal diamond consisting of at least 99.9% by weight isotopically pure carbon-12 or carbon-13, said diamond having a thermal conductivity of at least 31.5 watts/cm..degree.K. at 300.degree. K.
A method for preparing isotopically pure single-crystal diamond having a thermal conductivity of at least 31.5 watts/cm..degree.K. which comprises the steps of:
- (A) depositing a layer of at least 99.9% isotopically pure carbon-12 or carbon-13 diamond on a substrate by chemical vapor deposition, and
- (C) converting said isotopically pure diamond to single-crystal diamond by diffusion under high pressure through a metallic catalyst-solvent material to a region containing a diamond seed crystal.
A single-crystal diamond having a thermal conductivity of at least 31.5 watts/cm..degree.K. at 300.degree. K.
A method for preparing isotopically pure single-crystal diamond having a thermal conductivity of at least 31.5 watts/cm..degree.K. at 300.degree. K. which comprises the steps of:
- (A) producing isotopiclaly pure diamond at low pressure;
- and
- (B) converting said diamond into single-crystal diamond at high pressure.
Dependencies are inferred from the claim text.