Abstract: A method of producing a large area plate of single crystal diamond from CVD diamond grown on a substrate substantially free of surface defects by chemical vapor deposition (CVD). The homoepitaxial CVD grown diamond and the substrate are severed transverse to the surface of the substrate on which diamond growth took place to produce the large area plate of single crystal CVD diamond.

Abstract: A solid state system comprising a host material and a quantum spin defect, wherein the quantum spin defect has a T2 at room temperature of about 300 ?s or more and wherein the host material comprises a layer of single crystal CVD diamond having a total nitrogen concentration of about 20 ppb or less, wherein the surface roughness, Rq of the single crystal diamond within an area defined by a circle of radius of about 5 ?m centered on the point on the surface nearest to where the quantum spin defect is formed is about 10 nm or less, methods for preparing solid state systems and the use of single crystal diamond having a total nitrogen concentration of about 20 ppb or less in spintronic applications are described.

Abstract: A microwave plasma reactor for manufacturing synthetic diamond material via chemical vapour deposition, the microwave plasma reactor comprising: a plasma chamber; a substrate holder disposed in the plasma chamber and comprising a supporting surface for supporting a substrate on which the synthetic diamond material is to be deposited in use; a microwave coupling configuration for feeding microwaves from a microwave generator into the plasma chamber; and a gas flow system for feeding process gases into the plasma chamber and removing them therefrom; wherein the microwave plasma reactor further comprises an electrically conductive plasma stabilizing annulus disposed around the substrate holder within the plasma chamber.

Abstract: Single crystal diamond having a high chemical purity i.e. a low nitrogen content and a high isotopic purity i.e. a low 13C content, methods for producing the same and a solid state system comprising such single crystal diamond are described.

Abstract: A synthetic single crystal diamond material comprising: a first region comprising electron donor defects; a second region comprising quantum spin defects; and a third region between the first and second regions. The second and third regions have a lower concentration of electron donor defects than the first region. The first and second regions are sufficiently close to allow electrons to be donated from the first region to the second region, thus forming negatively charged quantum spin defects in the second and positively charged defects in the first region, and sufficiently far apart to reduce other coupling interactions between the first and second regions which would otherwise unduly reduce the decoherence time of the plurality of quantum spin defects and/or produce strain broaden of a spectral line width of the plurality of quantum spin defects in the second region.

Abstract: A method of producing a grown single crystal diamond substrate comprising: (a) providing a first diamond substrate which presents a (001) major surface, which major surface is bounded by at least one <100> edge, the length of the said at least one <100> edge exceeding any dimension of the surface that is orthogonal to the said at least one <100> edge by a ratio of at least 1.3:1; and (b) growing diamond material homoepitaxially on the (001) major surface of the diamond material surface under chemical vapour deposition (CVD) synthesis conditions, the diamond material growing both normal to the major (001) surface, and laterally therefrom.

Abstract: A polycrystalline CVD diamond material comprising a surface having a surface roughness Rq of less than 5 nm, wherein said surface is damage free to the extent that if an anisotropic thermal revealing etch is applied thereto, a number density of defects revealed by the anisotropic thermal revealing etch is less than 100 per mm2.

Abstract: A diamond layer of single crystal CVD diamond which is colored, preferably which has a fancy color, and which has a thickness of greater than 1 mm.

Abstract: A single crystal diamond prepared by CVD and having one or more electronic characteristics; making the diamond suitable for electronic applications. Also provided is a method of making the single crystal CVD diamond.

Abstract: The present invention relates to a method of producing a diamond surface including the steps of providing an original diamond surface, subjecting the original diamond surface to plasma etching to remove at least 2 nm of material from the original surface and produce a plasma etched surface, the roughness Rq of the plasma etched surface at the location of the etched surface where the greatest depth of material has been removed satisfying at least one of the following conditions: Rq of the plasma etched surface is less than 1.5 times the roughness of Rq of the original surface, or Rq of the plasma etched surface is less than 1 nm.

Abstract: An electrochemical sensor comprising: a reference electrode (4) formed of an electrically conductive synthetic doped diamond material and configured to be located in electrical contact with a solution (8) to be analysed; a sensing electrode (2) formed of an electrically conductive synthetic doped diamond material and configured to be located in contact with the solution (8) to be analysed; an electrical controller (10) configured to conduct stripping voltammetric measurements by applying a voltage to the sensing electrode (2), to change the applied voltage relative to the reference electrode (4), and to measure an electric current flowing through the sensing electrode (2) thereby generating voltammetry data; and a calibration system configured to provide an in-situ calibration for providing a reference point in the voltammetric data since the potential of the diamond reference electrode is non fixed and floating.

Abstract: A method of producing a CVD single crystal diamond layer on a substrate includes adding into a DVD synthesis atmosphere a gaseous source comprising silicon. The method can be used to mark the diamond material, for instance to provide means by which its synthetic nature can more easily be determined. It can also be exploited to generate single crystal diamond material of high color.

Abstract: The present disclosure relates to substrates for use in microwave plasma reactors. Certain substrates include a cylindrical disc of a carbide forming refractory metal having a flat growth surface on which CVD diamond is to be grown and a flat supporting surface opposed to said growth surface. The cylindrical disc may have a diameter of 80 mm or more. The growth surface may have a flatness variation no more than 100 mm The supporting surface may have a flatness variation no more than 100 mm.

Abstract: A microwave plasma reactor for manufacturing synthetic diamond material via chemical vapour deposition, the microwave plasma reactor comprising: a plasma chamber; a substrate holder disposed in the plasma chamber for supporting a substrate on which the synthetic diamond material is to be deposited in use; a microwave coupling configuration for feeding microwaves from a microwave generator into the plasma chamber; and a gas flow system for feeding process gases into the plasma chamber and removing them therefrom; wherein the gas flow system comprises a gas inlet nozzle array comprising a plurality of gas inlet nozzles disposed opposite the substrate holder for directing process gases towards the substrate holder, the gas inlet nozzle array comprising: at least six gas inlet nozzles disposed in a substantially parallel or divergent orientation relative to a central axis of the plasma chamber; a gas inlet nozzle number density equal to or greater than 0.

Abstract: A CVD single crystal diamond material suitable for use in, or as, an optical device or element. It is suitable for use in a wide range of optical applications such as, for example, optical windows, laser windows, optical reflectors, optical refractors and gratings, and etalons. The CVD diamond material is produced by a CVD method in the presence of a controlled low level of nitrogen to control the development of crystal defects and thus achieve a diamond material having key characteristics for optical applications.

Abstract: A CVD single crystal diamond material suitable for use in, or as, an optical device or element. It is suitable for use in a wide range of optical applications such as, for example, optical windows, laser windows, optical reflectors, optical refractors and gratings, and etalons. The CVD diamond material is produced by a CVD method in the presence of a controlled low level of nitrogen to control the development of crystal defects and thus achieve a diamond material having key characteristics for optical applications.

Abstract: A microwave plasma reactor for manufacturing synthetic diamond material via chemical vapor deposition, the microwave plasma reactor comprising: a microwave generator configured to generate microwaves at a frequency f; a plasma chamber comprising a base, a top plate, and a side wall extending from said base to said top plate defining a resonance cavity for supporting a microwave resonance mode between the base and the top plate; a microwave coupling configuration for feeding microwaves from the microwave generator into the plasma chamber; a gas flow system for feeding process gases into the plasma chamber and removing them therefrom; a substrate holder disposed in the plasma chamber and comprising a supporting surface for supporting a substrate; and a substrate disposed on the supporting surface, the substrate having a growth surface on which the synthetic diamond material is to be deposited in use, wherein the substrate dimensions and location within the resonance cavity are selected to generate a localized a

Abstract: A microwave plasma reactor for manufacturing synthetic diamond material via chemical vapour deposition, the microwave plasma reactor comprising: a microwave generator configured to generate microwaves at a frequency f; a plasma chamber comprising a base, a top plate, and a side wall extending from said base to said top plate defining a resonance cavity for supporting a microwave resonance mode between the base and the top plate; a microwave coupling configuration for feeding microwaves from the microwave generator into the plasma chamber; a gas flow system for feeding process gases into the plasma chamber and removing them therefrom; a substrate holder disposed in the plasma chamber and comprising a supporting surface for supporting a substrate; and a substrate disposed on the supporting surface, the substrate having a growth surface on which the synthetic diamond material is to be deposited in use, wherein the substrate dimensions and location within the resonance cavity are selected to generate a localized

Abstract: Microelectrode comprising a body formed from electrically non-conducting material and including at least one region of electrically conducting material and at least one passage extending through the body of non-conducting material and the region of conducting material, the electrically conducting region presenting an area of electrically conducting material to a fluid flowing through the passage in use. An electrochemical cell which includes such a microelectrode is also disclosed.

Abstract: An electrochemical sensor comprising: a reference electrode (4) formed of an electrically conductive synthetic doped diamond material and configured to be located in electrical contact with a solution (8) to be analysed; a sensing electrode (2) formed of an electrically conductive synthetic doped diamond material and configured to be located in contact with the solution (8) to be analysed; an electrical controller (10) configured to conduct stripping voltammetric measurements by applying a voltage to the sensing electrode (2), to change the applied voltage relative to the reference electrode (4), and to measure an electric current flowing through the sensing electrode (2) thereby generating voltammetry data; and a calibration system configured to provide an in-situ calibration for providing a reference point in the voltammetric data since the potential of the diamond reference electrode is non fixed and floating.