Provided is polycrystalline diamond having a diamond single phase as basic composition, in which the polycrystalline diamond includes a plurality of crystal grains and contains boron, at least either of nitrogen and silicon, and a remainder including 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 nitrogen and the silicon are present in an isolated substitutional type or an interstitial type in the crystal grains; each of the crystal grains has a grain size of less than or equal to 500 nm; and the polycrystalline diamond has a surface covered with a protective film.

A sensor system is based on diamonds with a high density of NV centers. The description includes a) methods for producing the necessary diamonds of high NV center density, b) characteristics of such diamonds, c) sensing elements for utilizing the fluorescence radiation of such diamonds, d) sensing elements for utilizing the photocurrent of such diamonds, e) systems for evaluating these quantities, f) reduced noise systems for evaluating these systems, g) enclosures for using such systems in automatic placement equipment, g) methods for testing these systems, and h) a musical instrument as an example of an ultimate application of all these devices and methods.

A sensor system is based on diamonds with a high density of NV centers. The description includes a) methods for producing the necessary diamonds of high NV center density, b) characteristics of such diamonds, c) sensing elements for utilizing the fluorescence radiation of such diamonds, d) sensing elements for utilizing the photocurrent of such diamonds, e) systems for evaluating these quantities, f) reduced noise systems for evaluating these systems, g) enclosures for using such systems in automatic placement equipment, g) methods for testing these systems, and h) a musical instrument as an example of an ultimate application of all these devices and methods.

A method of manufacturing a diamond substrate includes: forming an ion implantation layer at a side of a main surface of a diamond seed substrate by implanting ions into the main surface of the diamond seed substrate; producing a diamond structure by growing a diamond growth layer by a vapor phase synthesis method on the main surface of the diamond seed substrate, after implanting the ions; and performing heat treatment on the diamond structure. The performed heat treatment causes the diamond structure to be separated along the ion implantation layer into a first structure including the diamond seed substrate and failing to include the diamond growth layer, and a diamond substrate including the diamond growth layer. Thus, the method of manufacturing a diamond substrate is provided that enables a diamond substrate with a large area to be manufactured in a short time and at a low cost.

A method of manufacturing a diamond substrate includes: forming an ion implantation layer at a side of a main surface of a diamond seed substrate by implanting ions into the main surface of the diamond seed substrate; producing a diamond structure by growing a diamond growth layer by a vapor phase synthesis method on the main surface of the diamond seed substrate, after implanting the ions; and performing heat treatment on the diamond structure. The performed heat treatment causes the diamond structure to be separated along the ion implantation layer into a first structure including the diamond seed substrate and failing to include the diamond growth layer, and a diamond substrate including the diamond growth layer. Thus, the method of manufacturing a diamond substrate is provided that enables a diamond substrate with a large area to be manufactured in a short time and at a low cost.

A nanometer niobium carbide/carbon nanotube reinforced diamond composite and a preparation method thereof, belonging to the field of materials science. The nanometer niobium carbide/carbon nanotube reinforced diamond composite is composed of nanometer niobium carbide/carbon nanotube composite powders, matrix powders and diamond grains, wherein the nanometer niobium carbide/carbon nanotube composite powders are the composites of nanometer niobium carbide which are evenly distributed in the surface defects and interior of the carbon nanotube, the nanometer niobium carbide/carbon nanotube reinforced diamond composite is prepared by mixing the nanometer niobium carbide/carbon nanotube composite powders, matrix powders and diamond grains uniformly and sintering with a hot pressing technique.

A nanometer niobium carbide/carbon nanotube reinforced diamond composite and a preparation method thereof, belonging to the field of materials science. The nanometer niobium carbide/carbon nanotube reinforced diamond composite is composed of nanometer niobium carbide/carbon nanotube composite powders, matrix powders and diamond grains, wherein the nanometer niobium carbide/carbon nanotube composite powders are the composites of nanometer niobium carbide which are evenly distributed in the surface defects and interior of the carbon nanotube, the nanometer niobium carbide/carbon nanotube reinforced diamond composite is prepared by mixing the nanometer niobium carbide/carbon nanotube composite powders, matrix powders and diamond grains uniformly and sintering with a hot pressing technique.

A system for hydrocarbon decomposition comprising a reactor volume, a mechanism to distribute the liquid catalyst as a liquid mist, a distributor to distribute a hydrocarbon reactant, a heat source, a separator to separate the solid product from the liquid catalyst, a re-circulation path and mechanism to re-circulate the liquid catalyst, and an outlet for at least one gaseous product. A system to distribute a liquid to an enclosed volume as a mist has a plurality of orifices designed to break the liquid into a mist. A method to decompose a hydrocarbon reactant includes generating a mist of a liquid catalyst, heating the reactor volume, introducing a hydrocarbon reactant into the reactor volume to produce a solid product and a gaseous product, separating the solid product from the liquid catalyst, removing the solid and gaseous products from the reactor volume, and recirculating the liquid catalyst to the reactor volume.

A coated sliding member 10 for use under an environment where it is in contact with lubricant, comprising: a base material 12; and a first hard carbon layer 14 having a thickness of 3 μm or more formed on a surface of the base material by a vacuum arc method using carbon and consisting of diamond-like carbon, containing substantially no hydrogen and being configured only of carbon, and a second hard carbon layer 15 formed on a surface of the first hard carbon layer by a vacuum arc method using carbon and consisting of diamond-like carbon, containing substantially no hydrogen and being configured only of carbon and nitrogen, the film thickness of the second hard carbon layer being 3 to 35% of the film thickness of the first hard carbon layer.

A system for manufacturing a nanomaterial may include a first electrode; a second electrode spaced apart from the first electrode by a gap; and a chamber configured to enclose the first electrode, the second electrode, and a liquid. The system may also include a power supply configured to provide electrical energy to at least one of the first electrode and the second electrode; and a pump configured to cause the liquid to flow through the gap between the first electrode and the second electrode.