Patent ID: 11858856
Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 23:
24. Polycrystalline diamond having a diamond single phase as basic composition, wherein
the polycrystalline diamond includes a plurality of crystal grains,
the polycrystalline diamond contains boron, hydrogen, oxygen, and a remainder containing carbon and trace impurities,
the boron is dispersed in the crystal grains at an atomic level, and greater than or equal to 90 atomic % of the boron is present in an isolated substitutional type,
the hydrogen and the oxygen are present in an isolated substitutional type or an interstitial type in the crystal grains,
each of the crystal grain has a grain size of less than or equal to 500 nm,
the polycrystalline diamond has a surface covered with a protective film,
the boron has an atomic concentration of greater than or equal to 1×1014 cm−3 and less than or equal to 1×1022 cm−3,
the hydrogen has an atomic concentration of greater than or equal to 1×1017 cm−3 and less than or equal to 1×1020 cm−3,
the oxygen has an atomic concentration of greater than or equal to 1×1017 cm−3 and less than or equal to 1×1020 cm−3,
in a Raman spectroscopic measurement of the polycrystalline diamond, a peak area around 1575 cm−1±30 cm−1 with a half width of greater than 10 cm−1 and less than or equal to 20 cm−1 is less than 1% of a peak area around 1300 cm−1±30 cm−1 with a half width of less than or equal to 60 cm−1,
the surface of the polycrystalline diamond has a dynamic friction coefficient of less than or equal to 0.05,
the protective film contains a BOX cluster, at least one of O and OH that are an oxygen end of the carbon, and a precipitate precipitated out of the crystal grains,
the protective film has an average film thickness of greater than or equal to 1 nm and less than or equal to 1000 nm,
the polycrystalline diamond contains a graphene nanoribbon,
the polycrystalline diamond has a peak at a Raman shift of 1554 cm−1±20 cm−1 with a half width of less than or equal to 10 cm−1 in the Raman spectroscopic measurement, and
the polycrystalline diamond has a peak at a Raman shift of 2330 cm−1±20 cm−1 with a half width of less than or equal to 6 cm−1 in the Raman spectroscopic measurement, and
wherein the protective film is a graphene nanoribbon.