Abstract: A colorless and transparent, substantially inclusion-free diamond crystal which can be applied to decorative uses and optical parts is synthesized by a process using a temperature gradient method in an ultra-high pressure apparatus. This process comprises using, as a solvent for the growth of the crystal, at least one metal selected from the group consisting of Fe, Co, Ni, Mn and Cr (at least two metals in the case of containing Fe) and as a nitrogen getter for the removal of nitrogen in the solvent, at least one metal selected from the group consisting of Al, Ti, Zr, Hf, V, Nb and Ta in a proportion of 0.5 to 7% by weight (at most 2% by weight when using only Al) to the solvent metal.

Abstract: A polycrystalline carbon body is converted to a different crystallography by directing an infrared laser beam at a crystal boundary interface. By using a beam having a 5.3 micron wavelength so as to fall within a 5-9 micron range of normal spectral transmittance of the carbon, the interface is heated for solid state conversion by passing the beam through a forward portion of the body without appreciably heating the forward portion. During heating, the interface propagates through the body, thus converting an ever-decreasing aft portion of the body to the different crystallography.

Abstract: A transparent and scratchproof watch crystal, characterized in that it is made of polycrystalline diamond. The invention also concerns a watch case fitted with such a watch crystal.

Abstract: A method for solid state formation of diamond includes providing a diamond growth substrate, such as single-crystal silicon, forming on the diamond growth substrate an alloy of carbon and a metal which permits carbon to exist in a matrix therein, and causing carbon atoms from the alloy to precipitate on the diamond growth substrate in a diamond cubic lattice. The alloy may be an alloy of aluminum and carbon. The alloy is annealed in a hydrogen ambient to cause diffusion of hydrogen through the alloy to the surface of the substrate, providing a high concentration of hydrogen at the interface between the substrate and the alloy. The alloy is heated to cause carbon atoms in the alloy to diffuse through the alloy to the interface and form diamond.

Abstract: The object of the present invention is to provide a treatment method to remove lattice defects and non-diamond elements that exist in a diamond or a diamond thin film.The treatment method whereby the aforementioned object is achieved is to have the diamond or the diamond thin film irradiated by ultra-violet light or heated in an oxygen ambient.According to said treatment method, it has become possible to obtain a diamond or a diamond thin film that is free from the adverse effects of lattice defects and non-diamond elements.

Abstract: The present invention is related to a method of producing a nanoporous body containing nanodiamonds and having a desired shape, comprising the steps of: forming an intermediate body having the desired shape of nanodiamond particles having a maximum size of 10 nm, exposing said body to a gaseous hydrocarbon or a mixture of hydrocarbons at a temperature exceeding the decomposition temperature for the hydrocarbon or the hydrocarbons. In accordance with the invention the intermediate body is formed with a porosity of 50-80 vol. %, and during the heat treatment of the intermediate body with hydrocarbon or hydrocarbons, the mass of the body is increased by 50% at the most. The present invention also relates to a nanoporous body produced by the method and to uses of such a body.

Abstract: Diamond films and novel method to grow the diamond films can improve the performance of products utilizing diamond films. In the cathodoluminescence taken at room temperature, the integrated intensity ratio of the diamond films, CL.sub.1 /CL.sub.2, is equal or greater than 1/20, where CL.sub.1 is the integrated intensity of the emission band in the wavelength region shorter than 300 nm while CL.sub.2 is the integrated intensity of the emission band in the wavelength region from 300 nm to 800 nm. Such high quality diamond films with intensive coalescence on the surface can be obtained by deposition on the substrates or films, made of at least one member selected from the group consisting of platinum, platinum alloys, iridium, iridium alloys, nickel, nickel alloys, silicon, and metal silicides.

Abstract: A method for the growth of diamond on a substrate combines an ECR (Electron cyclotron resonance) MPCVD (Microwave plasma chemical vapor deposition) method with a MPCVD method in one system. A two-step diamond growing method comprises firstly etching and nucleation performed by the ECR method and then diamond grown by the microwave plasma CVD method. Not only are high quality continuous polycrystalline diamond films on silicon wafer obtained but also heteroepitaxial growth has been achieved in the present invention. Auger electron spectroscopy (AES), scanning electron microscopy (SEM) and Raman spectroscopy have been used to characterize the structure and morphology of the synthesized diamond films.

Abstract: There is provided a diamond crystal in which the (111) oriented plane is of the diamond crystal synthesized on a substrate by a chemical vapor deposition method parallel to a substrate surface, and the area of the (111) oriented plane parallel to the substrate surface is 1/24or less an area of the crystal on the substrate. A source gas is activated on a substrate consisting of a material which is not reactive with carbon. The source gas contains at least carbon and hydrogen in such a manner that the ratio of the number of carbon atoms to the total number of molecules of the source gas is 0.5% or less. Subsequently, a diamond crystal in which the (111) orientation plane is parallel to the substrate surface, and the area of the (111) orientation plane parallel to the substrate surface is precipitated on the substrate. A copper plate is preferably contains used as the substrate.

Abstract: Filamentous substrates are coated with diamond by a chemical vapor deposition process. The substrate may then be etched away to form a diamond filament, such as a diamond tube or a diamond fiber. In a preferred embodiment, the substrate is copper-coated graphite. The copper initially passivates the graphite, permitting diamond nucleation thereon. As deposition continues, the copper-coated graphite is etched away by the active hydrogen used in the deposition process. As a result a substrate-less diamond fiber is formed. Diamond-coated and diamond filaments are useful as reinforcement materials for composites, is filtration media in chemical and purification processes, in biomedical applications as probes and medicinal dispensers, and in such esoteric areas as chaff media for jamming RF frequencies.

Abstract: A diamond wafer including a substrate and a (100) oriented polycrystalline diamond film grown on the substrate for making surface acoustic wave devices, semiconductor devices or abrasion-resistant discs. The (100) oriented film is produced by changing a hydrocarbon ratio in a material gas halfway from a higher value to a lower value. The wafer is monotonously distorted with a distortion height H satisfying 2 .mu.m.ltoreq..vertline.H.vertline..ltoreq.150 .mu.m. The film is polished to a roughness of less than Rmax50 nm and Ra20 nm.

Abstract: A process for selective removal of residual carbon, such as graphite, from a mixture also containing a valuable material, such as diamonds, by selective oxidation using a silver oxide doped on copper oxide catalyst.

Abstract: A high purity synthetic diamond with less impurities, crystals defects, strains, etc. can be provided, in which the nitrogen content is at most 10 ppm, preferably at most 0.1 ppm and the boron content is at most 1 ppm, preferably at most 0.1 ppm or in which nitrogen atoms and boron atoms are contained in the crystal and the difference between the number of the nitrogen atoms and that of the boron atoms is at most 1.times.10.sup.17 atoms/cm.sup.3. The strain-free synthetic diamond can be produced by a process for the production of a strain-free synthetic diamond by the temperature gradient method, which comprises using a carbon source having a boron content of at most 10 ppm and a solvent metal having a boron content of at most 1 ppm and adding a nitrogen getter to the solvent metal, thereby synthesizing the diamond.

Abstract: A method for making diamonds by heating a heterogeneous dispersion of carbon made by the pyrolisis of an organic material and copper metal in a convenient pressure vessel while maintained at a pressure of 100,000 psi. The copper content of the reacting mass should be maintained within 15% of the total for best results.

Abstract: A synthetic single crystal diamond for wire drawing die; the process of manufacturing it and a wire drawing die to utilize it are disclosed. At least one plane of the diamond for wire drawing die is a cleavage plane of (111) faces, and the drawing hole of wire drawing die lies vertical to the cleavage plane.The diamond for the wire drawing die is produced by providing a synthetic single crystal having 20-400 ppm nitrogen of Ib type diamond. A groove is made on the diamond surface parallel to (111) faces employing energy beams such as a laser beam, an ion beam and an electron beam. A wedge is struck into the groove to cleave the diamond, and a plate is obtained. Furthermore, the plate is divided into polyhedrons, employing either an energy beam or a blade. The cleavage plane of the polyhedron is almost parallel to the (111) faces of crystal, therefore the cleavage plane is used as the standard plane to build the drawing hole.

Abstract: A method to grow diamond crystal by an utilization of liquid template on which carbon precursor is deposited. The liquid template is to replace the conventional solid template to improve the quality and the size of the diamond crystal through the inherent property of the liquid. Its ideal smoothness, its amorphosity and therefore, an absence of the grain boundary, and its high surface mobility for carbon aggregation to form diamond crystal, thus to grow diamond crystal.

Abstract: An article and method of manufacture of a nanocrystalline diamond film. The nanocrystalline film is prepared by forming a carbonaceous vapor, providing an inert gas containing gas stream and combining the gas stream with the carbonaceous containing vapor. A plasma of the combined vapor and gas stream is formed in a chamber and fragmented carbon species are deposited onto a substrate to form the nanocrystalline diamond film having a root mean square flatness of about 50 nm deviation from flatness in the as deposited state.

Abstract: A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein.

Abstract: A reaction vessel for use in producing large diamond crystals of good quality and yield includes a reaction volume and a reaction mass located in the volume. The reaction mass comprises a plurality of seed particles located in or on a surface in the reaction volume and a carbon source separated from the seed particles by a mass of metallic catalyst/solvent for diamond synthesis. The mass comprises alternating layers of carbon-rich and carbon-lean metallic catalyst/solvent which lie parallel or substantially parallel to the surface. There is also provided a mass of alternating layers of carbon-rich and carbon-lean metallic catalyst/solvent.

Abstract: A coated particle for synthesizing diamond includes: a single crystal of a fine diamond particle coated with at least one layer which contains at least one kind of solvent metal powder for synthesizing diamond and/or at least one kind of solvent metal powder with organic bonding material. Diamond abrasive particles for sawing are produced by a process which includes the steps of: coating fine diamond particles with at least one layer which contains at least one kind of solvent metal powder for synthesizing diamond and/or at least one kind of solvent metal powder with organic bonding material, filling a molding with the coated fine diamond particles, compacting, arranging a compact in a synthesizing vessel, heating the compact to a temperature above a solvent metal-graphite melting point under a pressure condition in which diamond is thermodynamically stable, and recovering the diamond abrasive particles.

Abstract: No wide bulk diamond wafer exists at present. A wide diamond-coated wafer is proposed instead of the bulk diamond wafer. Diamond is heteroepitaxially deposited on a convex-distorted non-diamond single crystal substrate by a vapor phase deposition method. In an early step, a negative bias is applied to the substrate. In the case of a Si substrate, an intermediate layer of .beta.-SiC is first deposited on the Si substrate by supplying a low carbon concentration material gas. Then the carbon concentration is raised for making a diamond film. The convex-distorted wafer is stuck to a holder having a shaft which is capable of inclining to the holder. The wafer is pushed to a turn-table of a polishing machine. The convex diamond wafer can fully be polished by inclining the holder to the shaft. A wide distorted mirror wafer of diamond is produced. Fine wire patterns can be made on the diamond mirror wafer by the photolithography.

Abstract: A synthesis of phosphorus-doped diamond by a microwave plasma method using a volatile hydrocarbon and hydrogen mixed therewith, as a reaction gas, wherein phosphorus is used as a dopant, and hydrogen bonded to the phosphorus is dissociated so that the phosphorus is introduced into diamond as an impurity without being bonded to hydrogen.

Abstract: Method and apparatus are disclosed for growing diamond films on a non-diamond substrate, such as a silicon wafer. The substrate surface is subjected to nucleation by means of a microwave-generated plasma while applying an electrical bias to the substrate and while an electrode is positioned adjacent to but spaced from the substrate surface. After the nucleation step, crystalline diamond is deposited on the nucleated surface from a carbon-containing plasma.

Abstract: Articles with a tenaciously adherent diamond coating are made by forming a diamond coating on a base material by vapor-phase synthesis without causing any warpage of the coating. The diamond coating layer is formed on the surface of a base material having a number of pores formed by electric discharge or laser beams and having a depth of 0.0001-0.2 mm and a diameter of 0.001-0.02 mm. The pores may be connected to one another to form a groove. Suitable examples of the base material include molybdenum, tungsten, silicon, tungsten carbide, silicon carbide, silicon nitride, and cemented carbide mainly comprising tungsten carbide and cobalt and/or nickel.

Abstract: A surface of a diamond, particularly a diamond window, is treated by depositing a layer of a carbide-forming metal such as titanium, on the surface and thereafter removing the layer. The treatment has the effect of passivating stress surface defects in the diamond such as grain boundaries, twin defects and polishing damage.

Abstract: The present invention relates to a diamond-carbon material, containing carbon, hydrogen, nitrogen, oxygen and incombustible impurities of a composition specified in the disclosure, and the surface contains methyl, carboxyl, lactone, aldehyde, ether and quinone groups.The material of the present invention is produced by detonating an oxygen-deficient explosive in a closed volume in a medium inert towards carbon, at a cooling rate of the detonation products of 200 to 6000 degree/min.

Abstract: A colorless, transparent low defect density, synthetic type IIa diamond single crystal, in which the etch pits due to needle-shaped defects are at most 3.times.10.sup.5 pieces/cm.sup.2, and which can be applied to uses needing high crystallinity of diamond, for example, monochromators, semiconductor substrates, spectroscopic crystals in X-ray range, electronic materials, etc., is provided by a process for the production of the colorless, transparent low defect density, synthetic diamond single crystal by growing new diamond crystal on a seed crystal of diamond by the temperature gradient method which comprises using a crystal defect-free diamond single crystal, as a seed crystal of diamond, and optionally subjecting to a heat treatment in a non-oxidizing atmosphere at a low pressure and a temperature of 1100 to 1600.degree. C.

Abstract: Processes are disclosed for performing non-microwave, non-arcjet plasma-assisted chemical vapor deposition of diamond in which substantially no particles impact the growing diamond surface with energies sufficient to prevent the growth of diamond. The energies of the particles are limited by selecting frequency, pressure, magnetic fields, electrical bias, or a combination thereof to the deposition region of the chamber. Diamond materials formed by these processes are also disclosed.

Abstract: Diamond materials are formed by sandwiching a carbon-containing material in a gap between two electrodes. A high-amperage electric current is applied between the two electrode plates so as cause rapid-heating of the carbon-containing material. The current is sufficient to cause heating of the carbon-containing material at a rate of at least approximately 5,000.degree. C./sec, and need only be applied for a fraction of a second to elevate the temperature of the carbon-containing material at least approximately 1000.degree. C. Upon terminating the current, the carbon-containing material is subjected to rapid-quenching (cooling). This may take the form of placing one or more of the electrodes in contact with a heat sink, such as a large steel table. The carbon-containing material may be rapidly-heated and rapidly-quenched (RHRQ) repeatedly (e.g., in cycles), until a diamond material is fabricated from the carbon-containing material.

Abstract: Hydrogenated amorphous carbon mainly composed of sp.sup.3 structure is prepared by adding hydrogen to carbon or decomposing hydrogenated carbon gas, and then rapidly cooling the mixed or decomposed gas on a substrate. The hydrogenated amorphous carbon is irradiated with X rays to excite electrons on the 1s shells of carbon atoms. The carbon atoms are rendered to a state excited with 2.sup.+ ion due to Auger effect caused by the exciation, so as to form atomic vacancies and interlattice atomic couples. The hydrogenated amorphous carbon is then annealed, and carbon atoms are rearranged to rotated triangular pattern. Thus, diamond good of crystallinity useful as a high-temperature semiconductor device, ultraviolet laser diode or protective film can be synthesized at a relatively low temperature and a low pressure. The process is applicable for the growth of a diamond single crystal thin film on a single crystal substrate such as amorphous carbon, silicon, or a Group III-V or II-VI compound semiconductor.

Abstract: A process for making diamond and diamond products includes the steps of implanting ions in a diamond substrate to form a damaged layer of non-diamond carbon below the top surface of the substrate, heating the substrate to about 600-1200.degree. C., growing diamond on the top surface of the heated substrate by chemical vapor deposition, and electrochemically etching the damaged layer to separate the grown diamond from the substrate along the damage layer. The diamond product consists of a first diamond layer and a second diamond layer attached to the first layer. The second layer contains damage caused by ions traversing the second layer.

Abstract: A method and system for fabricating porous polycrystalline diamond material whose volume is described by a dimension larger than 1 mm, with no upper limit on size. A net shape diamond part is fabricated by compacting small diamond particles into a mold and then performing chemical vapor deposition (CVD) growth of diamond on the particles until they are joined into a porous whole. The CVD growth of diamond is achieved by photofragmentation of vapor phase Fullerene, C.sub.60, molecules in the pores. C.sub.60 molecules are vaporized from solid C.sub.60 at a temperature of about 800.degree. C. The vapor diffuses into the voids between the diamond particles in the mold. The vapor is then subjected to intense illumination by a laser which causes the C.sub.60 molecules fragment. The deposition of these fragments causes diamond growth to occur on all surfaces around the pores between the particles. Continual replenishment of the C.sub.60 by the vapor source allows continuous deposition.

Abstract: A method is provided for efficiently producing an entirely quality-controlled CVD diamond. A CVD process is interrupted at an early stage and the deposit is taken out of the reaction chamber, before a significant mass is accumulated, and is inspected by means of cathodoluminescence. The spectrum are compared with a given reference in terms of peak position, half width and 20%-value width in coordination. The observed deviation allows to determine whether to maintain or alter the settings.A diamond substance of acceptable quality which is properly specified in terms of the CL parameters is also provided.

Abstract: Diamond coating member is produced by a method comprising a first coating step in which the first diamond coating layer is closely formed on fine irregularity parts of a substrate having fine irregularities substantially without void left between them and the fine irregularities is engaged with the above first layer to coat the above substrate, and a second coating step in which the surface of the first coating layer is coated with a second diamond coating layer comprising diamond having a higher wear resistance than that of the first coating layer. The diamond coating member is excellent in adhesion between the diamond coating layer and the substrate and has high durability without having the diamond coating layer scaled off by mechanical shocks. It has high wear resistance and enables mass production without fluctuation in product quality.

Abstract: High quality diamond excellent in crystalline property as well as transparency, can be synthesized at a high growth speed by a process which comprises using, as a raw material gas, a mixed gas of hydrogen gas A, an inert gas B, a carbon atom-containing gas C and an oxygen atom-containing inorganic gas D in such a proportion as satisfying the following relationship by mole ratio:0.001.ltoreq.B/(A+B+C+D).ltoreq.0.950.001.ltoreq.C/(A+B+C+D).ltoreq.0.10.0005.ltoreq.D/C.ltoreq.10except where a same gas is chosen from the carbon atom-containing gas C and the oxygen atom-containing inorganic gas D, feeding the mixed gas into a reactor in which plasma is then formed by applying a DC or AC electric field at a pressure of 10 to 760 torr and thereby depositing and forming diamond on a substrate arranged in the reactor.

Abstract: A composite structure for electronic components, having a base substrate with a flat side provided with a depression, and having a cover layer which is disposed on the flat side structured by the depression, and the depression being covered to form a hollow structure. The depression in the base substrate is created prior to the deposition of the cover layer and has a clear width measured parallel to the flat side that is less than one-half of its clear depth measured before the cover layer is applied. The vapor phase deposited cover layer is formed from a material which has a sufficiently high surface tension to promote three-dimensional growth of the vapor phase deposited layer.

Abstract: A diamond-containing material having the following element content ratio in per cent by weight: carbon 75-90, hydrogen 0.6-1.5, nitrogen 1.0-4.5, oxygen the balance, the following phase content ratio in per cent by weight: roentgen amorphous diamond-like phase 10-30, diamond of cubic modification the balance, and having a porous structure. 10-20% of the surface of the material consists of methyl, nitryl and hydroxyl groups of two types, as well as functional oxycarbonic groups of the general formula O.dbd.R where R represents .dbd.COH, .dbd.COOH, .dbd.CO, .dbd.C.sub.6 H.sub.4 O or any of their combinations, and 1-2% of the surface constits of carbon atoms with non-compensated links. A method for obtaining said material consists in detonation of a carbon-containing explosive substance with negative oxygen balance, or a mixture of explosive substances, in a closed volume in the atmosphere of gases inert to carbon, with an oxygen content of 0.1-6.

Abstract: A composition of matter in the form of an amorphous matrix having cesium dispersed therein is disclosed. The composition is capable of cold cathode emission, thus emitting electrons at wide range of temperatures, including room temperature. The matrix can be formed from amorphous diamond, diamond-like carbon, and other materials as well. Methods of making an amorphous matrix using single and multi-ion beam techniques are also disclosed.

Abstract: A diamond coated article is disclosed which consists essentially of a substrate and a plurality of polycrystalline diamond film layers accumulatively coated thereon in a total thickness of at least 20 .mu.m, wherein each of the polycrystalline diamond film layers (i) has a thickness of 6 to 13 .mu.m, (ii) has an average crystallite size in the surface direction thereof of 3 to 7 .mu.m, (iii) has (111) oriented diamond crystallites exposed on the surface thereof, and (iv) satisfies the relationship: I(N)I(D)<0.2, wherein I(D) represents an intensity of diamond Raman peak in counts/sec appearing around 1333 cm.sup.-1 and I(N) represents a maximum intensity among non-diamond Raman peaks appearing between 1200 cm.sup.-1 and 1600 cm.sup.-1.

Abstract: A method and system for manufacturing diamond film. The method involves forming a carbonaceous vapor, providing a gas stream of argon, hydrogen and hydrocarbon and combining the gas with the carbonaceous vapor, passing the combined carbonaceous vapor and gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the carbonaceous and deposition of a diamond film on a substrate.

Abstract: The invention relates to a composite structure including a semiconductor layer arranged on a diamond layer and/or a diamond-like layer, for subsequent processing to produce electronic components and/or groups of components and to a process for producing such a composite structure. In order to improve the quality of the subsequent components, the diamond layer is deposited underneath the component source zones from which the components are subsequently produced, and the diamond or diamond-like layer is provided at the margins of the component source zones and/or outside of the component source zones with edges where the thickness of the layer changes abruptly such that the edges have an edge height amounting to at least 1O%, preferably at least 50%, of the layer thickness of the diamond layer.

Abstract: A method of growing single crystal diamonds in excess of 10 .mu.m in diameter from industrial diamond "seeds" having mean diameters of approximately 1.5 .mu.m is disclosed. The diamonds are grown by exposing the seed diamonds to C.sub.70 in the presence of elemental reducing agents such as phosphorus or selenium in evacuated cells at moderate temperatures and pressures. In another aspect the invention diamonds are grown by exposing diamond seed particles to vapour phase C.sub.70 in the presence of a gas phase metal carbonyl, such as F.sub.5 e(CO) in a temperature range of 400.degree. C. to 700.degree. C. to cause at least some of the diamond seed particles to grow.

Abstract: A method is related to grow monocrystalline diamond films by chemical vapor deposition on large area at low cost. The substrate materials are either bulk single crystals of Pt or its alloys, or thin films of those materials deposited on suitable supporting materials. The surfaces of those substrates must be either (111) or (001), or must have domain structures consisting of (111) or (001) crystal surfaces. Those surfaces can be inclined within .+-.10 degree angles from (111) or (001). In order to increase the nucleation density of diamond, the substrate surface can be scratched by buff and/or ultrasonic polishing, or carbon implanted. Monocrystalline diamond films can be grown even though the substrate surfaces have been roughened. Plasma cleaning of substrate surfaces and annealing of Pt or its alloy films are effective in growing high quality monocrystalline diamond films.

Abstract: The present invention concerns a novel multilayer system comprising a diamond layer, and the method of manufacturing this multilayer system.The invention concerns a multilayer system comprising a metallic substrate, an interphase and a diamond layer, the interphase being composed of the product of thermal decomposition of at least one metallocene compound.This multilayer system, capable of being used as an electrode, has improved adhesion between the substrate and the diamond layer.

Abstract: A diamond covered member which has a diamond crystal layer is formed by vapor phase synthesis on a surface of a substrate. The process comprises depositing plate-shaped diamond crystals by CVD at a carbon source concentration ranging from 0.01 to 10% at an atomic ratio of oxygen to carbon (O/C) of 0.5.ltoreq.(O/C).ltoreq.1.2 in a starting gas. The crystals may also be deposited by a burning flame method using an oxygen-acetylene flame at a molar ratio of oxygen to acetylene in a main starting gas in the range of 0.9.ltoreq.(O.sub.2 /C.sub.2 H.sub.2).ltoreq.1.0. The plate-shaped diamond crystals are grown to coalesce into a film to form the diamond crystal layer.

Abstract: A method of forming devices having textured and highly oriented diamond layers includes the steps of forming a plurality of diamond nucleation sites on a substrate and then growing diamond on the sites so merge and form a continuous diamond layer having {100} and {111} facets. The growing step is performed by repeatedly cycling between first growth parameters, which favor growth of the nucleation sites in a direction normal to the {100} facets relative to growth in a direction normal to the {111} facets, and second growth parameters, which favor growth of the {100} facets relative to growth of the {111} facets, in sequence. This is continued until a diamond layer of desired thickness is obtained having large and substantially coplanar {100} facets. The first growth parameters are selected so that the rate of growth of diamond in a direction normal to the exposed {100} facets of the layer is preferably between about one and one quarter (1.25) times and one and three quarter (1.

Abstract: A method of making n-type semiconducting diamond is disclosed, which is doped with boron-10 at the time of diamond formation and bombarded with neutrons for in-situ conversion of boron-10 to lithium-7, while filtering the neutrons from high energy components during irradiation.

Abstract: A process for coating a substrate with diamond or diamond-like material including maintaining a substrate within a bed of particles capable of being fluidized, the particles having substantially uniform dimensions and the substrate characterized as having different dimensions than the bed particles, fluidizing the bed of particles, and depositing a coating of diamond or diamond-like material upon the substrate by chemical vapor deposition of a carbon-containing precursor gas mixture, the precursor gas mixture introduced into the fluidized bed under conditions resulting in excitation mechanisms sufficient to form the diamond coating.

Abstract: A diamond wafer including a substrate and a (100) oriented polycrystalline diamond film grown on the substrate for making surface acoustic wave devices, semiconductor devices or abrasion-resistant discs. The (100) oriented film is produced by changing a hydrocarbon ratio in a material gas halfway from a higher value to a lower value. The wafer is monotonously distorted with a distortion height H satisfying 2 .mu.m.ltoreq..vertline.H.vertline..ltoreq.150 .mu.m. The film is polished to a roughness of less than Rmax50 nm and Ra20 nm.

Abstract: High quality diamond excellent in crystalline property as well as transparency, can be synthesized at a high growth speed by a process which comprises using, as a raw material gas, a mixed gas of hydrogen gas A, an inert gas B, a carbon atom-containing gas C and an oxygen atom-containing inorganic gas D in such a proportion as satisfying the following relationship by mole ratio:0.001.ltoreq.B/(A+B+C+D).ltoreq.0.950.001.ltoreq.C/(A+B+C+D).ltoreq.0.10.0005.ltoreq.D/C.ltoreq.10except that the carbon atom-containing gas C and the oxygen atom-containing inorganic gas D, cannot simultaneously be the same gas feeding the mixed gas into a reactor in which plasma is then formed by applying a DC or AC electric field at a pressure of 10 to 760 torr and thereby depositing and forming diamond on a substrate arranged in the reactor.