Abstract: Monocrystalline diamond, adapted for use as in applications such as semiconductor devices, optical waveguides, and industrial applications, in the form of a single crystalline diamond structure having one or more diamond layers, at least one of which is formed by a CVD process. The diamond layers are “lattice-matched” or “lattice-mismatched” to each other to provide a desired level of strain.

Abstract: The invention provides a mass of crystals, particularly diamond crystals, having a size of less than 100 microns and in which mass the majority of the crystals are faceted single crystals. The invention further provides a method of producing such a mass of crystals which utilizes crystal growth under elevated temperature and pressure conditions, the supersaturation driving force necessary for crystal growth being dependent, at least in part, on the difference in surface free energy between low Miller index surfaces and high Miller index surfaces of the crystals. Preferably, the method is carried out under conditions where the Wulff effect dominates.

Abstract: A method of making a Schottky diode comprising the steps of: providing a single crystal diamond comprising a surface; placing the single crystal diamond in a CVD system; heating the diamond to a temperature of at least about 950° C.; providing a gas mixture capable of growing diamond film and comprising a sulfur compound through the CVD system; growing an epitaxial diamond film on the surface of the single crystal diamond; baking the diamond at a temperature of at least about 650° C. in air for a period of time that minimizes oxidation of the diamond; and fabricating a Schottky diode comprising the diamond film. A Schottky diode comprising an epitaxial diamond film and capable of blocking at least about 6 kV in a distance of no more than about 300 &mgr;m.

Abstract: MEMS structure and a method of fabricating them from ultrananocrystalline diamond films having average grain sizes of less than about 10 nm and feature resolution of less than about one micron . The MEMS structures are made by contacting carbon dimer species with an oxide substrate forming a carbide layer on the surface onto which ultrananocrystalline diamond having average grain sizes of less than about 10 nm is deposited. Thereafter, microfabrication process are used to form a structure of predetermined shape having a feature resolution of less than about one micron.

Abstract: An electrically conducting n-type ultrananocrystalline diamond (UNCD) having no less than 1019 atoms/cm3 of nitrogen is disclosed. A method of making the n-doped UNCD. A method for predictably controlling the conductivity is also disclosed.

Abstract: An ultra-hard semiconductive polycrystalline diamond (PCD) material formed with semiconductive diamond particles doped with and additive, as for example, Li, Be or Al and/or insulative diamond particles having semiconductive surfaces, tools incorporating the same, and methods for forming the same, are provided. The ultra-hard PCD material may be formed using a layer of insulative diamond grit feedstock that includes additives therein, then sintering to convert a plurality of the diamond crystals to include a semiconductive surface. In another embodiment, the ultra-hard PCD material is formed by sintering semiconductive diamond grit feedstock consisting of diamond crystals doped with an additive as for example Li, Al or Be. The ultra-hard semiconductive PCD cutting layer exhibits increased cuttability, especially in EDM and EDG cutting operations. A cutting element is provided having such a PCD layer. Furthermore, a bit is provided having a cutting element having such a PCD layer.

Abstract: A new class of carbon materials and their synthesis. The new carbon materials are formed by high pressure and high temperature processing of fullerene based carbon powder. The new carbon materials are harder than graphite and can be harder than steel (what the starting fullerenes are single wall nanotubes) or almost as hard as diamond (when the starting fullerened arm C60 buckyballs). The physical attributes of the materials can also be controlled by the pressing and heating parameters. These new carbon materials are conductive like graphite and unlike diamond which is an insulator. The materials can be formed by powder metallurgy techniques into any shape (cylinders, balls, tubes, rods, cones, foils, fibers or others). The new materials can also be readily doped, converted to diamond, formed within a porous composite or converted to diamond within the porous composite.

Abstract: The present invention is directed to a method for changing the color of colored natural diamonds. The method includes placing a discolored natural diamond in a pressure-transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature for a time sufficient to improve the color of the diamond. The diamond may be exposed at elevated-pressure and elevated-temperature conditions within the graphite-stable region of the carbon-phase diagram—without significant graphitization of the diamond, or above the diamond-graphite equilibrium and within the diamond-stable region of the carbon-phase diagram. Finally, the diamond is recovered from said press. Colorless Type Ia and Type II diamonds may be made by this method.

Abstract: The invention provides a mass of crystals, particularly diamond crystals, having a size of less that 100 microns and in which mass the majority of the crystals are faceted single crystals. The invention further provides a method of producing such a mass of crystals which utilises crystal growth under elevated temperature and pressure conditions, the supersaturation driving force necessary for crystal growth being dependent, at least in part, on the difference in surface free energy between low Miller index surfaces and high Miller index surfaces of the crystal. Preferably, the method is carried out under conditions where the Wulff effect dominates.

Abstract: An organic chemical made of acetamide, urea and the like is mixed with water to form a mixture thereof, which is heated to form a given reacted sample. In order to remove water and volatile organic matters, the reacted sample is frozen and dried, and then, heated under vacuum condition to create diamond.

Abstract: A method for forming a superhard polycrystalline diamond or diamond-like element with greatly improved resistance to thermal degradation without loss of impact strength. Collectively called PCD elements, these elements are formed with a binder-catalyzing material in a high-temperature, high-pressure process. The PCD element has a plurality of partially bonded diamond or diamond-like crystals forming at least one continuous diamond matrix, and the interstices among the diamond crystals forming at least one continuous interstitial matrix containing a catalyzing material. The element has a working surface and a body, where a portion of the interstitial matrix in the body adjacent to the working surface is substantially free of the catalyzing material to a depth from the working surface, the remaining interstitial matrix contains the catalyzing material, causing a 950 degrees C. temperature at the working surface to be less than 750 degrees C. at the depth.

Abstract: One of the principal objectives is to provide a loose mass of single crystalline minute diamond particles for abrasive uses, which is prepared from a coarser crystalline product of a common static ultra high-pressure process. The novel particle abrasive can achieve improvement in both machining efficiency (stock removal per time) and worked surface roughness. An effective method for its production is also provided.

Abstract: The present invention is directed to a method for changing the color of colored natural diamonds. The method includes placing a discolored natural diamond in a pressure-transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature for a time sufficient to improve the color of the diamond. The diamond may be exposed at elevated-pressure and elevated-temperature conditions within the graphite-stable region of the carbon-phase diagram—without significant graphitization of the diamond, or above the diamond-graphite equilibrium and within the diamond-stable region of the carbon-phase diagram. Finally, the diamond is recovered from said press. Colorless Type Ia and Type II diamonds may be made by this method.

Abstract: A method for synthesizing boron doped diamond for improving the oxidation resistance of said diamond crystals includes forming a fully dense core (mixture) of graphite, catalyst/solvent metals, optional diamond seed crystals, and a source of boron. This mixture is subjected to diamond-formed high pressure/high temperature (HP/HT) conditions for a time adequate for forming diamond. The thus-formed diamond product is recovered to contain boron substituted into the diamond structure. The fully dense core is substantially devoid of air/nitrogen (N) content. In one embodiment, the boron amorphous B.

Abstract: A liquid crystal display cell having liquid crystal molecules positioned in a vertical or a substantially vertical alignment is provided. The liquid crystal display cell includes at least two substantially homogeneous fluorinated alignment layers disposed on transparent electrodes; a liquid crystal layer of liquid crystal molecules disposed between the alignment layers; and, a means of applying voltage across the transparent electrodes. Methods for forming these liquid crystal display cells are also provided.

Abstract: A diamond cluster includes a core and an overgrown region containing a plurality of diamond crystallites extending outwards from the core, the majority of the crystallites having a cross-sectional area which increases as the distance of the crystallite from the core increases. Generally, at least 80% of the crystallites have a cross-sectional area which increases as the distance of the crystallite from the core increases. Furthermore, a method of producing a plurality of the diamond clusters includes the stops of providing a source of carbon, providing a plurality of growth center particles, each comprising a bonded mass of constituent particles, producing a reaction mass by bringing the carbon source and growth center particles into contact with a solvent/catalyst, subjecting the reaction mass to conditions of elevated temperature and pressure suitable for crystal growth, and recovering a plurality of diamond clusters from the reaction mass.

Abstract: n aqueous suspension liquid of finely divided diamond particles comprising 0.05 to 160 parts by weight of a finely divided diamond particles in 1000 parts of water, wherein; (i) the finely divided diamond particles have an element composition consisting mainly of 72 to 89.5% by weight of carbon, 0.8 to 1.5% of hydrogen, 1.5 to 2.5% of nitrogen, and 10.5 to 25.0% of oxygen; (ii) and, almost all of said diamond particles are in the range of 2 nm to 50 nm in diameters thereof (80% or more by number average, 70% or more by weight average), (iii) and, said finely divided diamond particles exhibit a strongest peak of the intensity of the Bragg angle at 43.9° (2&thgr;±2°), strong and characteristic peaks at 73.5° (2&thgr;±2°)and 95° (2&thgr;±2°), a warped halo at 17°(2&thgr;±2°), and no peak at 26.

Abstract: A method for making diamond material comprises providing a deposition chamber; placing a substrate in said deposition chamber; sealing and evacuating said deposition chamber; admitting to said deposition chamber gases suitable for diamond deposition; heating said substrate to a diamond deposition temperature; igniting and maintaining a plasma adjacent to a growth surface of said substrate such that said plasma extends no further than 1 mm from said growth surface of said substrate; and maintaining said plasma during a diamond deposition time period.

Abstract: An object of the present invention is to provide a method for producing diamond and cubic boron nitride crystals having excellent mechanical strength and high regularity in particle size with high productivity, wherein seed crystals are efficiently placed in a regular pattern on a supporting plate or a raw material plate.

Abstract: A self-grown monopoly compact grit and high pressure, high temperature process for preparing the same. The high pressure, high temperature sintered/synthesized monopoly compact grit is used in various industrial tools such as saw blades, grinding wheels, cutting tools and drill bits. Further, the monopoly compact grit of the present invention is produced from a seed of a mono-crystal of diamond or cubic boron nitride surrounded by either a self-grown crystal layer or an integrally bonded poly-crystalline sintered compact layer. The self-grown crystal layer is a new grown crystal structure where the seed crystal grows into a new phase through a normal diamond or cubic boron nitride synthesis process in the presence of a catalyst metal solvent.

Abstract: The present invention is directed to a method for changing the color of colored natural diamonds. The method includes placing a discolored natural diamond in a pressure-transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature for a time sufficient to improve the color of the diamond. The diamond may be exposed at elevated-pressure and elevated-temperature conditions within the graphite-stable region of the carbon-phase diagram—without significant graphitization of the diamond, or above the diamond-graphite equilibrium and within the diamond-stable region of the carbon-phase diagram. Finally, the diamond is recovered from said press. Colorless Type Ia and Type II diamonds may be made by this method.

Abstract: A method for controlling the crystallite size and growth rate of plasma-deposited diamond films. A plasma is established at a pressure in excess of about 55 Torr with controlled concentrations of hydrogen up to about 98% by volume, of unsubstituted hydrocarbons up to about 3% by volume and an inert gas of one or more of the noble gases and nitrogen up to about 98% by volume. The volume ratio of inert gas to hydrogen is preferably maintained at greater than about 4, to deposit a diamond film on a suitable substrate. The diamond film is deposited with a predetermined crystallite size and at a predetermined growth rate.

Abstract: Synthetic monocrystalline diamond compositions having one or more monocrystalline diamond layers formed by chemical vapor deposition, the layers including one or more layers having an increased concentration of one or more impurities (such as boron and/or isotopes of carbon), as compared to other layers or comparable layers without such impurities. Such compositions provide an improved combination of properties, including color, strength, velocity of sound, electrical conductivity, and control of defects. A related method for preparing such a composition is also described, as well as a system for use in performing such a method, and articles incorporating such a composition.

Abstract: A method for producing a preferably optical polycrystalline diamond element is provided. A substrate having a surface which is complementary to said element is molded and is coated by means of diamond deposition. The diamond element is then removed from the mold. The diamond element is finished either before or after being removed from the mold. The substrate is machine cut in order to form the complementary molded product having at least one spherical surface, whereupon it is covered with a polycrystalline diamond by chemical vapor deposition (CVD).

Abstract: A method of making a bonded, coherent material comprising a mass of crystals, preferably diamond crystals, in a matrix is provided. The steps include providing a source of the crystals of the type to be grown and which are substantially free of macroscopically faceted surfaces, producing a reaction mass by bringing the source crystals into contact with a suitable solvent/catalyst, subjecting the reaction mass to conditions of elevated temperature and pressure suitable for crystal growth in the reaction zone of a high temperature/high pressure apparatus to produce the material and removing the material from the reaction zone, the conditions of crystal growth being chosen such that the source crystals are converted to crystals having developed macroscopic facets of low Miller index. Preferably the conditions of elevated temperature and pressure used are such that the Wulff effect dominates.

Abstract: A hard carbon film-coated substrate is disclosed which has between a substrate and a hard carbon film an interlayer principally comprised of at least one selected from the group consisting of Al, Cr, Sn, Co and B, oxides, nitrides and carbides thereof.

Abstract: The present invention relates to a method for manufacturing a highly purified diamond. In the method, a copper powder having purity 99.8% or more and having an acid-insoluble impurity concentration at 50 ppm or less, and graphite are mixed at first. The mixture of the copper powder and graphite is loaded into a sample tube. The sample tube is placed in an explosive tube. Explosive is loaded in the surrounding of the sample tube. Graphite is shock-compressed by the detonation of the explosive to yield diamond.

Abstract: A low free energy method for more rapidly diffusing an impurity as exemplified by boron, into a natural or synthetic diamond or other crystalline element in powdered or granular form, without degradation of the crystalline structure. The present method includes the steps of providing a mixture of the diamond or other crystalline element and the impurity in a solid phase; treating the mixture to bring the impurity into conforming contact with the outer surface of the crystalline element; and heating the mixture to a temperature between about 200° C. and about 2000° C. As an example, a diamond is disclosed having boron as an impurity diffused into the crystalline structure thereof by the present method, at a ratio of from about 0.1 part of the impurity per 1 million parts of the diamond to about 600 parts of the impurity per 1 million parts of the diamond.

Abstract: A method for synthesizing boron doped diamond for improving the oxidation resistance of said diamond crystals includes forming a fully dense core (mixture) of graphite, catalyst/solvent metals, optional diamond seed crystals, and a source of boron. This mixture is subjected to diamond-formed high pressure/high temperature (HP/HT) conditions for a time adequate for forming diamond. The thus-formed diamond product is recovered to contain boron substituted into the diamond structure. The fully dense core is substantially devoid of nitrogen (N) content, which mostly comes from air. Thus, the fully dense core is substantially devoid of air. The preferred source of B is amorphous B; although other sources of B can be used to form the boron-doped, blue diamond of the present invention.

Abstract: A method of forming a fluorine-bearing diamond layer on non-diamond substrates, especially on tool substrates comprising a metal matrix and hard particles, such as tungsten carbide particles, in the metal matrix. The substrate and a fluorine-bearing plasma or other gas are then contacted under temperature and pressure conditions effective to nucleate fluorine-bearing diamond on the substrate. A tool insert substrate is treated prior to the diamond nucleation and growth operation by etching both the metal matrix and the hard particles using suitable etchants.

Abstract: Diamond crystals may be grown by providing a source of diamond crystals, providing a plurality of growth centers defined by diamond crystals, mixing the source and growth center diamond crystals with a solvent/catalyst in particulate form to form a reaction mass, subjecting the reaction mass to conditions of elevated temperature and pressure suitable for crystal growth, and recovering the diamond crystals. The necessary supersaturation of carbon is achieved in the solvent/catalyst, at least in part, and preferably predominantly, by a selection of the particle size difference between the source crystal and the growth centers. The mass of diamond crystals produced by this method has a high concentration of twinned diamonds.

Abstract: The present invention is directed to a method for treating discolored natural diamond, especially Type IIa diamond and Type IaA/B diamond with nitrogen as predominantly B centers, for improving its color. The method includes placing a discolored natural diamond in pressure transmitting medium powder which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature within the diamond stable range of the carbon phase diagram for a time sufficient to improve the color of said diamond. Finally, the diamond is recovered from said press. Colorless diamond can be made by this method.

Abstract: A method for controlling the crystallite size and growth rate of plasma-deposited diamond films. A plasma is established at a pressure in excess of about 55 Torr with controlled concentrations of hydrogen up to about 98% by volume, of unsubstituted hydrocarbons up to about 3% by volume and an inert gas of one or more of the noble gases and nitrogen up to about 98% by volume. The volume ratio of inert gas to hydrogen is preferably maintained at greater than about 4, to deposit a diamond film on a suitable substrate. The diamond film is deposited with a predetermined crystallite size and at a predetermined growth rate.

Abstract: The invention offers a hard carbon film and a SAW substrate that are easy to fabricate or low in manufacturing cost while virtually maintaining the quality that affects the important properties of a device that comprises the hard carbon film or the SAW substrate. The hard carbon film comprises a composite film of graphite-like diamond and carbon clusters; the composite film has a continuous crystal structure.

Abstract: The present invention is directed to a method for treating discolored natural diamond, especially Type IIa diamond and Type IaA/B diamond with nitrogen as predominantly B centers, for improving its color. The method includes placing a discolored natural diamond in pressure transmitting medium powder which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature within the diamond stable range of the carbon phase diagram for a time sufficient to improve the color of said diamond. Finally, the diamond is recovered from said press. Colorless diamond can be made by this method.

Abstract: The method of making a diamond product in accordance with the present invention comprises the steps of forming a diamond substrate (50) with a mask layer (52), and etching the diamond substrate (50) formed with the mask layer (52) with a plasma of a mixed gas composed of a gas containing an oxygen atom and a gas containing a fluorine atom, whereas the fluorine atom concentration is within the range of 0.04% to 6% with respect to the total number of atoms in the mixed gas.

Abstract: The present invention relates to a method for manufacturing a highly purified diamond. In the method, a copper powder having purity 99.8% or more and having an acid-insoluble impurity concentration at 50 ppm or less, and graphite are mixed at first. The mixture of the copper powder and graphite is loaded into a sample tube. The sample tube is placed in an explosive tube. Explosive is loaded in the surrounding of the sample tube. Graphite is shock-compressed by the detonation of the explosive to yield diamond.

Abstract: A method of forming a diamond film includes synthesizing a diamond film on a surface of a substrate, where the surface of the substrate has trenches. The trenches inhibit delamination of the diamond film.

Abstract: The present invention relates generally to methods for the synthesis of various solids such as diamonds, diamonds films, boron nitride and other similar materials. This invention specifically relates to utilizing novel sources of reaction species (e.g., in the case of diamond formation, novel sources of carbon and/or hydrogen and/or seeds) for the manufacture of various materials and the use of such materials for various commercial purposes.

Abstract: In synthesizing a diamond by a vapor-phase growth method, a sputtering method, or a high-pressure and high-temperature synthesis method, N, P or As as an n-type dopant, and H as a p-type dopant are simultaneously doped in a crystal to form a donor-acceptor pair in the crystal, to thereby synthesize a transparent n-type diamond having low resistance.

Abstract: An optical filter using alternating layers of materials with “low” and “high” indices of refraction and deposited with atomic layer control has been developed. The multilayered thin film filter uses, but is not limited to, alternating amorphous layers of atomically controlled Si (n=3.56) as the high index material and diamond-like carbon (DLC, n=2.0) as the low index material. The Si layers are grown with a self-limiting pulsed molecular beam deposition process which results in layer-by-layer growth and thickness control to within one atomic layer. The DLC layers are produced using an ion-based process and made atomically smooth using a modified Chemical Reactive-Ion Surface Planarization (CRISP) process. Intrinsic stress is monitored using an in-situ cantilever-based intrinsic stress optical monitor and adjusted during filter fabrication by deposition parameter modification.

Abstract: The principal objects of the invention is to provide diamond fine particles with a surface nature so improved as to form a stable, uniform suspension or dispersion in a common medium such as water and alcohol. Another object is to provide an effective technique for producing hydrophilic diamond fine particles by chemically modifying the particle surface nature, while removing at the same time contaminants and foreign materials which coexist with the diamond. In the invention, diamond particles are treated by boiling in the treatment fluid of sulfuric acid solution, which is in particular of concentrated or fuming nature, at a temperature more than 200° C., which is preferably 250° C. or more.

Abstract: An element-doped diamond crystal is disclosed herein. The crystal includes at least one dopant element which has a greater concentration toward or near an outermost surface of the crystal than in the center of the crystal. The concentration of the dopant element is at a local minimum at least about 5 micrometers below the surface. The concentration-profile of the dopant element for these diamond crystals causes an expansion of the diamond lattice, thereby generating tangential compressive stresses at the surface of the diamond crystal. These stresses beneficially increase the compressive fracture strength of the diamond.

Abstract: The present invention is directed to a method for treating discolored natural diamond, especially Type IIa diamond and Type IaA/B diamond with nitrogen as predominantly B centers, for improving its color. The method includes placing a discolored natural diamond in a pressure transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature within the graphite stable range of the carbon phase diagram for a time sufficient to improve the color of said diamond. Finally, the diamond is recovered from said press. Colorless diamond can be made by this method.

Abstract: The method of the present invention includes placing a solid dopant in or near the nozzle of a DC arc jet. According to one embodiment of the invention, the interior surface of an arc jet nozzle is coated with a layer of copper by brushing the surface with a copper brush. According to another embodiment of the invention, the interior surface of an arc jet nozzle is coated with a layer of copper by plating it with copper. According to another embodiment of the invention, a copper cylinder is placed inside an arc jet nozzle. Apparatus according to the invention include a DC arc jet with a solid dopant placed in or near the nozzle according to one of the methods described. Diamonds according to the invention are conductive diamonds formed by a plasma jet process where a solid dopant was placed in or near the nozzle according to one of the methods described.

Abstract: A method of making a bonded, coherent material comprising a mass of diamond crystals in a matrix, which optionally contains another phase. The method includes the steps of providing a source of diamond crystals, providing a plurality of diamond centers defined by diamond crystals, producing a reaction mass by bringing the source and growth centers into contact with a solvent/catalyst, subjecting the reaction mass to conditions of elevated temperature and pressure suitable for crystal growth in the reaction zone of a high temperature/high pressure apparatus to produce the material, and removing the material from the reaction zone. The method is characterized by providing the necessary supersaturation of carbon in the solvent/catalyst, at least in part and preferably predominantly, by a selection of particle size difference between the source crystal and the growth centers. The mass of diamond crystals in the matrix of the bonded, coherent material of the invention has a high concentration of twinned diamonds.

Abstract: A DC plasma jet CVD process having a high film deposition rate is employed. A material having low adhesion with diamond is used for a substrate. A diamond film automatically peels from the substrate at the time of cooling. Gas is recycled because gas utilization efficiency is low. In this case, deposition of carbon can be prevented by setting a gas flow velocity to at least 5 m/s in the proximity of an anodic point.

Abstract: A fuel injector comprising a fuel inlet arranged, in use, to receive fuel under high pressure from a source of pressurised fuel, an outlet and an accumulator volume located between the inlet and the outlet. A piezoelectric actuator is located within the accumulator volume and is operable to move a control piston to modify the fuel pressure within a control chamber.

Abstract: Diamond having a large coefficient of thermal conductivity is prepared by a CVD method in which a reaction gas is decomposed and reacted under such condition that a concentration of carbon atoms in relation to hydrogen gas (A %), a concentration of nitrogen gas in relation to the whole reaction gas (B ppm) and a concentration of oxygen atoms in relation to the hydrogen gas (C %) satisfy the equation:.alpha.=B.times.(A-1.2C) (I)provided that a is not larger than 13, or B is not larger than 20.

Abstract: A diamond powder, comprises diamond powder particles, and polar and non-polar groups, bonded onto surfaces of the particles. This seed diamond powder and a dispersed solution thereof can be used to seed a substrate for the deposition of diamond at a high nucleation density for chemical vapor deposition of synthetic diamond.