| 摘要 |
This single crystal diamond is configured of carbon that has a carbon isotope 12C concentration of 99.9% by mass or more and a plurality of unavoidable impurities other than carbon. The unavoidable impurities include nitrogen, boron, hydrogen and nickel; and the total content of nitrogen, boron and hydrogen among the plurality of unavoidable impurities is set to 0.01% by mass or less. In order to produce the single crystal diamond, a hydrocarbon gas having a carbon isotope 12C concentration of 99.9% by mass or more is first subjected to a denitrification treatment (S1). The hydrocarbon gas having been subjected to the denitrification treatment is thermally decomposed on a substrate within a vacuum chamber, for example, at a temperature from 1,200°C to 2,300°C (inclusive), thereby preparing a carbon starting material (S2). Diamond is synthesized with use of this carbon starting material, and a seed crystal is cut out of the diamond (S3). This seed crystal is contained in a cell together with a solvent and a carbon source, and single crystal diamond is grown from the seed crystal by a high-temperature high-pressure synthesis method (S4). |
