| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide polycrystalline nanodiamond utilizable to magnetic sensing, and to provide a production method thereof. <P>SOLUTION: This polycrystalline nanodiamond 1 is composed of carbon with ≥99.9 mass% purity of<SP POS="POST">12</SP>C carbon isotope, and a plurality of impurities other than carbon, where the concentration of the plurality of impurities is each 0.01 mass% or less, and the crystal grain diameter is 500 nm or less. This polycrystalline nanodiamond 1 has ≥99.9 mass% purity of<SP POS="POST">12</SP>C carbon isotope, and can be produced by pyrolyzing hydrocarbon gas with ≥99 mass% chemical purity to obtain graphite, and applying heat treatment to the obtained graphite in a high temperature, high pressure press machine to convert the graphite into diamond. <P>COPYRIGHT: (C)2013,JPO&INPIT |
