Abstract: Provided are a diamond composite body capable of shortening a separation time for separating a substrate and a diamond layer, the substrate, and a method for manufacturing a diamond, as well as a diamond obtained from the diamond composite body and a tool including the diamond. The diamond composite body includes a substrate including a diamond seed crystal and having grooves in a main surface, a diamond layer formed on the main surface of the substrate, and a non-diamond layer formed on a substrate side at a constant depth from an interface between the substrate and the diamond layer.

Abstract: A diamond polycrystal includes diamond grains, the diamond polycrystal including a cubic diamond and a 6H type hexagonal diamond, wherein the cubic diamond and the 6H type hexagonal diamond exist in the same or different diamond grains, and a ratio Ab1/Ab2 is more than or equal to 0.4 and less than or equal to 1, Ab1 representing a maximum value of absorption in a range of more than or equal to 1200 cm?1 and less than or equal to 1300 cm?1 in an infrared absorption spectrum, Ab2 representing a maximum value of absorption in a range of more than or equal to 1900 cm?1 and less than or equal to 2100 cm?1.

Abstract: Nano polycrystalline diamond is composed of carbon, an element of different type which is an element other than carbon and is added to be dispersed in carbon at an atomic level, and an inevitable impurity. The polycrystalline diamond has a crystal grain size not greater than 500 nm. The polycrystalline diamond can be fabricated by subjecting graphite in which the element of different type which is an element other than carbon has been added to be dispersed in carbon at an atomic level to heat treatment within high-pressure press equipment.

Abstract: In a diamond polycrystal, a value of a ratio (d?/d) of d? to d is less than or equal to 0.98 in a Vickers hardness test performed under a condition defined in JIS Z 2244:2009, where the d represents a length of a diagonal line of a first Vickers indentation formed in a surface of the diamond polycrystal when a Vickers indenter with a test load of 4.9 N is pressed onto the surface of the diamond polycrystal, and the d? represents a length of a diagonal line of a second Vickers indentation remaining in the surface of the diamond polycrystal after releasing the test load.

Abstract: In a diamond polycrystal, a value of a ratio (a?/a) of a? to a is less than or equal to 0.99 in a Knoop hardness test performed under a condition defined in JIS Z 2251:2009, where the a represents a length of a longer diagonal line of a first Knoop indentation formed in a surface of the diamond polycrystal when a Knoop indenter with a test load of 4.9 N is pressed onto the surface of the diamond polycrystal, and the a? represents a length of a longer diagonal line of a second Knoop indentation remaining in the surface of the diamond polycrystal after releasing the test load.

Abstract: A synthetic single crystal diamond contains nitrogen atoms at a concentration of more than 600 ppm and 1500 ppm or less, and the nitrogen atoms do not include any isolated substitutional nitrogen atom.

Abstract: A diamond polycrystal is a diamond polycrystal basically composed of a diamond single phase, wherein the diamond polycrystal is composed of a plurality of diamond grains having an average grain size of less than or equal to 30 nm, and the diamond polycrystal has a carbon dangling bond density of more than or equal to 10 ppm.

Abstract: In a single-crystal diamond material, a concentration of non-substitutional nitrogen atoms is not more than 200 ppm, a concentration of substitutional nitrogen atoms is lower than the concentration of the non-substitutional nitrogen atoms, and the single-crystal diamond material has a crystal growth main surface having an off angle of not more than 20°. A perforated tool includes a single-crystal diamond die, wherein in the single-crystal diamond die, a concentration of non-substitutional nitrogen atoms is not more than 200 ppm, a concentration of substitutional nitrogen atoms is lower than the concentration of the non-substitutional nitrogen atoms, and the single-crystal diamond die has a low-index plane represented by a Miller index of not less than ?5 and not more than 5 in an integer, a perpendicular line of the low-index plane having an off angle of not more than 20° relative to an orientation of a hole for wire drawing.

Abstract: Provided is a synthetic single crystal diamond containing nitrogen atoms at a concentration of more than 600 ppm and 1500 ppm or less. The Raman shift ?? (cm?1) of a peak in a primary Raman scattering spectrum of the synthetic single crystal diamond and the Raman shift ? (cm?1) of a peak in a primary Raman scattering spectrum of a synthetic type IIa single crystal diamond containing nitrogen atoms at a content of 1 ppm or less satisfy the following expression (1): ??????0.10??(1).

Abstract: Provided is a method for manufacturing a single-crystal diamond, the method including the steps of: forming a protective film on at least a part of a surface of an auxiliary plate; preparing a diamond seed crystal substrate; disposing an auxiliary plate with a protective film that has the protective film formed on the auxiliary plate, and a diamond seed crystal substrate in a chamber; and growing a single-crystal diamond on a principal surface of the diamond seed crystal substrate by a chemical vapor deposition method while introducing a carbon-containing gas into the chamber.

Abstract: A composite polycrystal includes: a polycrystalline diamond phase including a plurality of diamond particles; and non-diamond phases composed of non-diamond carbon. The non-diamond phases are distributed in the polycrystalline diamond phase. An average value of projected area equivalent circle diameters of the non-diamond phases is not more than 1000 nm.

Abstract: In an X-ray topography image for a crystal growth main surface of a single-crystal diamond, a group of crystal defect points are gathered, each of the crystal defect points being a tip point of a crystal defect line reaching the crystal growth main surface, the crystal defect line representing a line in which a crystal defect exists. Further, in the single-crystal diamond, a plurality of crystal defect line-like gathered regions exist in parallel. In the plurality of crystal defect line-like gathered regions, groups of crystal defect points are gathered to extend in the form of lines in a direction angled by not more than 30° relative to one arbitrarily specified direction. Accordingly, a single-crystal diamond is provided which is used suitably for a cutting tool, a polishing tool, an optical component, an electronic component, a semiconductor material, and the like.

Abstract: A method of manufacturing a diamond by a vapor phase synthesis method includes: preparing a substrate including a diamond seed crystal; forming a light absorbing layer lower in optical transparency than the substrate by performing ion implantation into the substrate, the light absorbing layer being formed at a predetermined depth from a main surface of the substrate; growing a diamond layer on the main surface of the substrate by the vapor phase synthesis method; and separating the diamond layer from the substrate by applying light from a main surface of at least one of the diamond layer and the substrate to allow the light absorbing layer to absorb the light and cause the light absorbing layer to be broken up.

Abstract: A method of manufacturing a diamond by a vapor phase synthesis method includes: preparing a substrate including a diamond seed crystal; forming a light absorbing layer lower in optical transparency than the substrate by performing ion implantation into the substrate, the light absorbing layer being formed at a predetermined depth from a main surface of the substrate; growing a diamond layer on the main surface of the substrate by the vapor phase synthesis method; and separating the diamond layer from the substrate by applying light from a main surface of at least one of the diamond layer and the substrate to allow the light absorbing layer to absorb the light and cause the light absorbing layer to be broken up.

Abstract: 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.

Abstract: It is an object to provide a cubic boron nitride polycrystalline material excellent in toughness. A cubic boron nitride polycrystalline material containing fine cubic boron nitride which is granular, has a maximum grain size not greater than 100 nm, and has an average grain size not greater than 70 nm and at least one of plate-shaped cubic boron nitride in a form of a plate having an average major radius not smaller than 50 nm and not greater than 10000 nm and coarse cubic boron nitride which is granular, has a minimum grain size exceeding 100 nm, and has an average grain size not greater than 1000 nm is provided.

Abstract: The present diamond single crystal is a diamond single crystal containing nitrogen atoms, in which a concentration of the nitrogen atoms changes periodically along a crystal orientation of the diamond single crystal, and an arithmetic average value Aave, a maximum value Amax, and a minimum value Amin of the distance of one period along the crystal orientation satisfy the relationship expressed by the following equation (I): (Amax)/1.25?(Aave)?(Amin)/0.75??(I).

Abstract: A cubic boron nitride polycrystal includes cubic boron nitride, the cubic boron nitride having an average grain size of not more than 150 nm, the cubic boron nitride polycrystal having a crack generation load of not less than 25 N in a breaking strength test in which an R200 ?m diamond indenter is used to apply a load at a rate of 100 N/min.

Abstract: A composite sintered body includes a diamond phase and a non-diamond carbon phase. A non-diamond carbon phase occupancy rate is higher than 0% and not higher than 30%. The non-diamond carbon phase occupancy rate is a percentage of an area of the non-diamond carbon phase to a total area of one arbitrarily specified cross section of the composite sintered body. As a result, there is provided a high wear-resistant, high local wear-resistant and high chipping-resistant diamond-containing composite sintered body suitably used as a material for a wear-resistant tool, a cutting tool and the like.

Abstract: A composite polycrystal contains polycrystalline diamond formed of diamond grains that are directly bonded mutually, and compressed graphite dispersed in the polycrystalline diamond.