Abstract: The present invention discloses methods to produce large quantities of polycrystalline GaN for use in the ammonothermal growth of group III-nitride material. High production rates of GaN can be produced in a hydride vapor phase growth system. One drawback to enhanced polycrystalline growth is the increased incorporation of impurities, such as oxygen. A new reactor design using non-oxide material that reduces impurity concentrations is disclosed. Purification of remaining source material after an ammonothermal growth is also disclosed. The methods described produce sufficient quantities of polycrystalline GaN source material for the ammonothermal growth of group III-nitride material.

Abstract: The present invention provides a method for growing group III-nitride crystals wherein the group III-nitride crystal growth occurs on an etched seed crystal. The etched seed is fabricated prior to growth using a temperature profile which produces a high solubility of the group III-nitride material in a seed crystals zone as compared to a source materials zone. The measured X-ray diffraction of the obtained crystals have significantly narrower Full Width at Half Maximum values as compared to crystals grown without etch back of the seed crystal surfaces prior to growth.

Abstract: A method for producing a nitride semiconductor, comprising controlling temperature and pressure in a autoclave containing a seed having a hexagonal crystal structure, a nitrogen element-containing solvent, a raw material substance containing a metal element of Group 13 of the Periodic Table, and a mineralizer so as to put said solvent into a supercritical state and/or a subcritical state and thereby ammonothermally grow a nitride semiconductor crystal on the surface of said seed, wherein the crystal growth rate in the m-axis direction on said seed is 1.5 times or more the crystal growth rate in the c-axis direction on said seed. By the method, a nitride semiconductor having a large-diameter C plane or a nitride semiconductor thick in the m-axis direction can be efficiently and simply produced.

Abstract: A method for producing a high-quality group-III element nitride crystal at a high crystal growth rate, and a group-III element nitride crystal are provided. The method includes the steps of placing a group-III element, an alkali metal, and a seed crystal of group-III element nitride in a crystal growth vessel, pressurizing and heating the crystal growth vessel in an atmosphere of nitrogen-containing gas, and causing the group-III element and nitrogen to react with each other in a melt of the group-III element, the alkali metal and the nitrogen so that a group-III element nitride crystal is grown using the seed crystal as a nucleus. A hydrocarbon having a boiling point higher than the melting point of the alkali metal is added before the pressurization and heating of the crystal growth vessel.

Abstract: A technique for growing high quality bulk hexagonal single crystals using a solvo-thermal method, and a technique for achieving the high quality and high growth rate at the same time. The crystal quality strongly depends on the growth planes, wherein a nonpolar or semipolar seed surface such as {10-10}, {10-11}, {10-1-1}, {10-12}, {10-1-2}, {11-20}, {11-22}, {11-2-2} gives a higher crystal quality as compared to a c-plane seed surface such as (0001) and (000-1). Also, the growth rate strongly depends on the growth planes, wherein a semipolar seed surface such as {10-12}, {10-1-2}, {11-22}, {11-2-2} gives a higher growth rate. High crystal quality and high growth rate are achievable at the same time by choosing the suitable growth plane.

Abstract: A method for manufacturing a single crystal of nitride by epitaxial growth on a substrate appropriate for the growth of the crystal. The substrate includes, deposited on the edges of its growth surface, a mask appropriate to prevent growing of the single crystal on the edges of the substrate.

Abstract: The present invention discloses a high-pressure vessel of large size formed with a limited size of e.g. Ni—Cr based precipitation hardenable superalloy. The vessel may have multiple zones. For instance, the high-pressure vessel may be divided into at least three regions with flow-restricting devices and the crystallization region is set higher temperature than other regions. This structure helps to reliably seal both ends of the high-pressure vessel, and at the same time, may help to greatly reduce unfavorable precipitation of group III nitride at the bottom of the vessel. This invention also discloses novel procedures to grow crystals with improved purity, transparency and structural quality. Alkali metal-containing mineralizers are charged with minimum exposure to oxygen and moisture until the high-pressure vessel is filled with ammonia. Several methods to reduce oxygen contamination during the process steps are presented.

Abstract: A method for producing a GaN crystal capable of achieving at least one of the prevention of nucleation and the growth of a high-quality non-polar surface is provided. The production method of the present invention is a method for producing a GaN crystal in a melt containing at least an alkali metal and gallium, including an adjustment step of adjusting the carbon content of the melt, and a reaction step of causing the gallium and nitrogen to react with each other. According to the production method of the present invention, nucleation can be prevented, and as shown in FIG. 4, a non-polar surface can be grown.

Abstract: Purification techniques have been developed for ceramic powder precursors, e.g., barium nitrate. These techniques can be performed using one or more of the following operations: (1) removal of impurities by precipitation or coprecipitation and separation using a nonmetallic-ion-containing strong base, e.g., tetraalkylammonium hydroxides; (2) reduction of higher oxidation-state-number oxymetal ions and subsequent precipitation as hydroxides that are separated from the solution; and (3) use of liquid-liquid exchange extraction procedures to separate certain impurities.

Abstract: In the direct production of GaN by the metathesis of Li3N and GaCl3 or GaBr3 or GaI3, the reaction rate and yields can be greatly enhanced by including diethyl ether in the reaction system.

Abstract: The invention relates to a stent with in particular a coated basic body made of an implant material the use of lithium salts as a coating material or a component of an implant material for stents and the use of lithium salts in a method for restenosis prevention. The inventive stent having a basic body made of an implant material is characterized in that (i) the basic body has a coating which comprises or consists of a lithium salt, and/or (ii) the implant material is biocorrodible and the basic body contains a lithium salt.

Abstract: Provided is a thermal expansion inhibitor which has a much broader application range and which can be used with ease. Used is a thermal expansion inhibitor comprising a manganese nitride crystal.

Abstract: It is provided a melt composition for growing a gallium nitride single crystal by flux method. The melt composition contains gallium, sodium and barium, and a content of barium is 0.05 to 0.3 mol % with respect to 100 mol % of sodium.

Abstract: A method of dividing single crystals, particularly of plates of parts thereof, is proposed, which can comprise: pre-adjusting the crystallographic cleavage plane (2?) relative to the cleavage device, setting a tensional intensity (K) by means of tensional fields (3?, 4?), determining an energy release rate G(?) in dependence from a possible deflection angle (?) from the cleavage plane (2?) upon crack propagation, controlling the tensional fields (3?, 4?) such that the crack further propagates in the single crystal, wherein G(0)?2?e(0) and simultaneously at least one of the following conditions is satisfied: ? ? G ? ? ? ? = 0 ? 2 ? ? e h ? ? if ? ? ? 2 ? G ? ? 2 ? 0 ? ? or ( 2.1 ) ? ? G ? ? ? ? 2 ? ? e h ? ? ? ? : ? ? 1 < ? < ? 2 , ( 2.

Abstract: The present invention relates to a fabrication method of gallium manganese nitride (GaMnN) single crystal nanowire, more particularly to a fabrication method of GaMnN single crystal nanowire substrate by halide vapor phase epitaxy (HVPE) in which such metal components as gallium (Ga) and manganese (Mn) react with such gas components as nitrogen (N2), hydrogen chloride (HCl) and ammonia (NH3), wherein the amount of the gas components are adjusted to control the Mn doping concentration in order to obtain nanowire having a perfect, one-dimensional, single crystal structure without internal defect, concentration of holes, or carriers, and magnetization value of which being determined by the doping concentration and showing ferromagnetism at room temperature, thus being a useful spin transporter in the field of the next-generation spintronics, such as spin-polarized LED, spin-polarized FET, etc.

Abstract: A transition metal nitride is obtained by a nitriding treatment of a surface of a base material including a transition metal or an alloy of the transition metal, and the transition metal nitride has a crystal structure of an M4N type and a crystal structure of an ?-M2˜3N type, and is formed over a whole area of the surface of the base material and continuously in a depth direction from the surface.

Abstract: The powder of an Nb compound has a composition represented by NbxOy, NbxNz or NbxOyNz. The powder of the Nb compound has an electric conductivity which is not less than 1/10 of that of Nb. A porous sintered body used for manufacturing a solid electrolytic capacitor is formed using the powder of the Nb compound. The solid electrolytic capacitor achieves both of a reduction in size and an increase in capacitance.

Abstract: The present invention provides an apparatus for manufacturing a group-III nitride semiconductor layer having high crystallinity. An embodiment of the present invention provides an apparatus for manufacturing a group-III nitride semiconductor layer on a substrate 11 using a sputtering method. The apparatus includes: a chamber 41; a target 47 that is arranged in the chamber 41 and includes a group-III element; a first plasma generating means 51 that generates a first plasma for sputtering the target 47 to supply raw material particles to the substrate 11; a second plasma generating means 52 that generates a second plasma including a nitrogen element; and a control means that controls the first plasma generating means 51 and the second plasma generating means 52 to alternately generate the first plasma and the second plasma in the chamber 41.

Abstract: A method of forming a bulk, free-standing cubic III-N substrate including a) growing epitaxial III-N material on a cubic III-V substrate using molecular beam epitaxy (MBE); and b) removing the III-V substrate to leave the III-N material as a bulk, free-standing cubic III-N substrate. A bulk, free-standing cubic III-N substrate for fabrication of III-N devices.

Abstract: To control the precipitation position of a crystal and increase the yield of the crystal by performing the crystal growth according to the solvothermal method while allowing a predetermined amount of a substance differing in the critical density from the solvent to be present in the reaction vessel; and to prevent mixing of an impurity into the crystal and improve the crystal purity.

Abstract: Disclosed is a method of manufacturing a GaN-based material having high thermal conductivity. A gallium nitride-based material is grown by HVPE (Hydride Vapor Phase Epitaxial Growth) by supplying a carrier gas (G1) containing H2 gas, GaCl gas (G2), and NH3 gas (G3) to a reaction chamber (10), and setting the growth temperature at 900 (° C.) (inclusive) to 1,200 (° C.) (inclusive), the growth pressure at 8.08×104 (Pa) (inclusive) to 1.21×105 (Pa) (inclusive), the partial pressure of the GaCl gas (G2) at 1.0×104 (Pa) (inclusive) to 1.0×104 (Pa) (inclusive), and the partial pressure of the NH3 gas (G3) at 9.1×102 (Pa) (inclusive) to 2.0×104 (Pa) (inclusive).

Abstract: A method forms a gallium nitride crystal sheet. According to the method a metal melt, including gallium, is brought to a vacuum of 0.01 Pa or lower and is heated to a growth temperature of between approximately 860° C. and approximately 870° C. A nitrogen plasma is applied to the surface of the melt at a sub-atmospheric working pressure, until a gallium nitride crystal sheet is formed on top. Preferably, the growth temperature is of 863° C., and the working pressure is within the range of 0.05 Pa and 2.5 Pa. Application of the plasma includes introducing nitrogen gas to the metal melt at the working pressure, igniting the gas into plasma, directing the plasma to the surface of the metal melt, until gallium nitride crystals crystallize thereon, and maintaining the working pressure and the directed plasma until a gallium nitride crystal sheet is formed.

Abstract: A crystal has a diameter of 1 cm or more and shows a strongest peak in cathode luminescent spectrum at a wavelength of 360 nm in correspondence to a band edge.

Abstract: A gallium nitride crystal with a polyhedron shape having exposed {10-10} m-planes and an exposed (000-1) N-polar c-plane, wherein a surface area of the exposed (000-1) N-polar c-plane is more than 10 mm2 and a total surface area of the exposed {10-10} m-planes is larger than half of the surface area of (000-1) N-polar c-plane. The GaN bulk crystals were grown by an ammonothermal method with a higher temperature and temperature difference than is used conventionally, and using an autoclave having a high-pressure vessel with an upper region and a lower region. The temperature of the lower region of the high-pressure vessel is at or above 550° C., the temperature of the upper region of the high-pressure vessel is set at or above 500° C., and the temperature difference between the lower and upper regions is maintained at or above 30° C. GaN seed crystals having a longest dimension along the c-axis and exposed large area m-planes are used.

Abstract: Provided are a III/V group nitride semiconductor causing an oxidation-reduction reaction at a high photoconversion efficiency by irradiation of light, a photocatalytic semiconductor device, a photocatalytic oxidation-reduction reaction apparatus, and an execution process of a photoelectrochemical reaction. In the III/V group nitride semiconductor, the full width at half maximum of an X-ray rocking curve on a catalytic reaction surface thereof is 400 arcsec or less, and a carrier density in a surface layer portion having the catalytic reaction surface is 1.5×1016 cm?3 or more, but 3.0×1018 cm?3 or less. The photocatalytic semiconductor device has the III/V group nitride semiconductor laminated on a substrate.

Abstract: The present invention relates to a method of preparing a Li film, wherein said Li film is fabricated by directly decomposing a compound of Li under a vacuum evaporation condition, and said compound is Li3N. Said Li film is fabricated by decomposing Li3N at an evaporation rate of 0.01-0.25 nm/s and an evaporation temperature of 300-450° C., and said Li film has a thickness of 0.3-5.0 nm.

Abstract: Provided is a thermal expansion inhibitor which has a much broader application range and which can be used with ease. Used is a thermal expansion inhibitor comprising a manganese nitride crystal.

Abstract: A GaN substrate having a large diameter of two inches or more by which a semiconductor device such as a light emitting element with improved characteristics such as luminance efficiency, an operating life and the like can be obtained at low cost industrially, a substrate having an epitaxial layer formed on the GaN substrate, a semiconductor device, and a method of manufacturing the GaN substrate are provided. A GaN substrate has a main surface and contains a low-defect crystal region and a defect concentrated region adjacent to low-defect crystal region. Low-defect crystal region and defect concentrated region extend from the main surface to a back surface positioned on the opposite side of the main surface. A plane direction [0001] is inclined in an off-angle direction with respect to a normal vector of the main surface.

Abstract: A process for producing a Group 13 metal nitride crystal, comprising performing the growth of a Group 13 metal nitride crystal in a solution or melt comprising an ionic solvent having dissolved therein a composite nitride containing a metal element belonging to Group 13 of the Periodic Table and a metal element other than Group 13 of the Periodic Table. According to this production process, a good-quality Group 13 metal nitride crystal can be produced under low or atmospheric pressure by an industrially inexpensive method.

Abstract: Manufacture at lower cost of off-axis GaN single-crystal freestanding substrates having a crystal orientation that is displaced from (0001) instead of (0001) exact. With an off-axis (111) GaAs wafer as a starting substrate, GaN is vapor-deposited onto the starting substrate, which grows GaN crystal that is inclined at the same off-axis angle and in the same direction as is the starting substrate. Misoriented freestanding GaN substrates may be manufactured, utilizing a misoriented (111) GaAs baseplate as a starting substrate, by forming onto the starting substrate a mask having a plurality of apertures, depositing through the mask a GaN single-crystal layer, and then removing the starting substrate. The manufacture of GaN crystal having a misorientation of 0.1° to 25° is made possible.

Abstract: A manufacturing apparatus of Group III nitride crystals and a method for manufacturing Group III nitride crystals are provided, by which high quality crystals can be manufactured. For instance, crystals are grown using the apparatus of the present invention as follows. A crystal raw material (131) and gas containing nitrogen are introduced into a reactor vessel (120), to which heat is applied by a heater (110), and crystals are grown in an atmosphere of pressure applied thereto. The gas is introduced from a gas supplying device (180) to the reactor vessel (120) through a gas inlet of the reactor vessel, and then is exhausted to the inside of a pressure-resistant vessel (102) through a gas outlet of the reactor vessel. Since the gas is introduced directly to the reactor vessel (120) without passing through the pressure-resistant vessel (102), the mixture of impurities attached to the pressure-resistant vessel (102) and the like into the site of the crystal growth can be prevented.

Abstract: A method for forming ammonia is disclosed and which includes the steps of forming a plasma; providing a source of metal particles, and supplying the metal particles to the plasma to form metal nitride particles; and providing a substance, and reacting the metal nitride particles with the substance to produce ammonia, and an oxide byproduct.

Abstract: To provide a method for efficiently producing a high quality metal nitride containing a small amount of impurities, particularly gallium nitride. A method for producing a metal nitride characterized by employing a container made of a nonoxide material. By using a nonoxide for a material of a container to be in contact with a raw metal or a metal nitride to be formed, reaction or adhesion of the raw metal or the metal nitride to be formed to the container can be avoided, and inclusion of oxygen derived from the material of the container can be prevented, whereby a high quality metal nitride having high crystallinity will be obtained. By securing a certain or larger supply amount and a certain or higher flow rate of the nitrogen source gas, the raw metal can be converted into a nitride with an extremely high conversion, and a metal nitride having a small amount of an unreacted raw metal remaining and containing a metal and nitrogen in a stoichiometric constant can be obtained with a high yield.

Abstract: A method of preparing a high purity metal nitride and/or oxide powder is provided, comprising: heating a metal salt and an organic fuel to an ignition temperature in a nitrogen-rich atmosphere, forming a first composition; and optionally heating the first composition to a heat treatment temperature, which heat treatment temperature is above the ignition temperature and below 1000° C., in a nitrogen-rich atmosphere until the metal nitride and/or oxide powder is formed.

Abstract: The present invention provides compositions and a novel high-yielding process for preparing high purity Group III nitrides. The process involves heating a Group III metal and a catalytic amount of a metal wetting agent in the presence of a nitrogen source. Group III metals can be stoichiometrically converted into high purity Group III nitride powders in a short period of time. The process can provide multi-gram quantities of high purity Group III nitrides in relatively short reaction times. Detailed characterizations of GaN powder were preformed and are reported herein, including morphology and structure by SEM and XRD, optical properties by cathodoluminescence (CL), and Raman spectra to determine the quality of the GaN particles. The purity of GaN powder was found to be greater than 99.9% pure, as analyzed by Glow Discharge Mass Spectrometry (GDMS). Green, yellow, and red light emission can be obtained from doped GaN powders.

Abstract: Large area single crystal III-V nitride material having an area of at least 2 cm2, having a uniformly low dislocation density not exceeding 3×106 dislocations per cm2 of growth surface area, and including a plurality of distinct regions having elevated impurity concentration, wherein each distinct region has at least one dimension greater than 50 microns, is disclosed. Such material can be formed on a substrate by a process including (i) a first phase of growing the III-V nitride material on the substrate under pitted growth conditions, e.g., forming pits over at least 50% of the growth surface of the III-V nitride material, wherein the pit density on the growth surface is at least 102 pits/cm2 of the growth surface, and (ii) a second phase of growing the III-V nitride material under pit-filling conditions.

Abstract: A method of growing group III-nitride crystals in a mixture of supercritical ammonia and nitrogen, and the group-III crystals grown by this method. The group III-nitride crystal is grown in a reaction vessel in supercritical ammonia using a source material or nutrient that is polycrystalline group III-nitride, amorphous group III-nitride, group-III metal or a mixture of the above, and a seed crystal that is a group-III nitride single crystal. In order to grow high-quality group III-nitride crystals, the crystallization temperature is set at 550° C. or higher. Theoretical calculations show that dissociation of NH3 at this temperature is significant. However, the dissociation of NH3 is avoided by adding extra N2 pressure after filling the reaction vessel with NH3.

Abstract: A crystal producing apparatus includes a crystal forming unit and a crystal growing unit. The crystal forming unit forms a first gallium nitride (GaN) crystal by supplying nitride gas into melt mixture containing metal sodium (Na) and metal gallium (Ga). The first GaN crystal is sliced and polished to form GaN wafers. The crystal growing unit grows a second GaN crystal on a substrate formed by using a GaN wafer, by the hydride vapor phase epitaxy method, thus producing a bulked GaN crystal.

Abstract: A simple, inexpensive method of producing in bulk a doped metal nitride powder that exhibits a high luminescent efficiency, by first forming a metal-dopant alloy and then reacting the alloy with high purity ammonia under controlled conditions in a reactor. The resulting doped metal nitride powders will exhibit a luminescent efficiency that greatly exceeds that seen in pure undoped GaN powders, doped GaN thin films, and ZnS powders.

Abstract: Dendron ligands or other branched ligands with cross-linkable groups were coordinated to colloidal inorganic nanoparticles, including nanocrystals, and substantially globally cross-linked through different strategies, such as ring-closing metathesis (RCM), dendrimer-bridging methods, and the like. This global cross-linking reaction sealed each nanocrystal within a dendron box to yield box-nanocrystals which showed dramatically enhanced stability against chemical, photochemical and thermal treatments in comparison to the non-cross-linked dendron-nanocrystals. Empty dendron boxes possessing a very narrow size distribution were formed by the dissolution of the inorganic nanocrystals contained therein upon acid or other etching treatments.

Abstract: In a crystal preparing device, a crucible holds a mixed molten metal containing alkali metal and group III metal. A container has a container space contacting the mixed molten metal and holds a molten alkali metal between the container space and an outside of the container, the molten alkali metal contacting the container space. A gas supply device supplies nitrogen gas to the container space. A heating device heats the crucible to a crystal growth temperature. The crystal preparing device is provided so that a vapor pressure of the alkali metal which evaporates from the molten alkali metal is substantially equal to a vapor pressure of the alkali metal which evaporates from the mixed molten metal.

Abstract: A method of producing high quality GaN powder by combining high purity gallium and high purity ammonia in a tube reactor under controlled conditions. A reaction between the ammonia and gallium under the controlled conditions produces a porous gallium melt and to a full reaction, yielding high purity crystalline GaN powders with a stoichiometric nitrogen concentration and a hexagonal wurtzite structure.

Abstract: A method is provided for the preparation of a hydrogen storage medium having a high hydrogen storage capacity, high reversibility and fast reaction time. A high storage capacity Li3N-containing media with high reversibility is also provided.

Abstract: The invention concerns a method for calcium nitride synthesis which consists in spraying in form of droplets, by means of a sprayer, a molten zinc-calcium alloy into a reactor containing nitrogen at high temperature. The resulting calcium nitride is collected in a collector unit at the lower part of the reactor. The zinc contained in the droplets is evaporated and condensed on the cooled walls of the reactor and can be reused for preparing another alloy. The zinc-calcium alloy is obtained by electrolysis of calcium chloride in an electrolytic cell whereof the cathode is a solution containing molten zinc.

Abstract: A method of manufacturing a nanocrystallite from a M-containing salt forms a nanocrystallite. The nanocrystallite can be a member of a population of nanocrystallites having a narrow size distribution and can include one or more semiconductor materials. Semiconducting nanocrystallites can photoluminesce and can have high emission quantum efficiencies.

Abstract: Polycrystalline materials of macroscopic size exhibiting Single-Crystal-Like properties are formed from a plurality of Single-Crystal Particles, having Self-Aligning morphologies and optionally ling morphology, bonded together and aligned along at least one, and up to three, crystallographic directions.

Abstract: In a capacitor comprising a pair of electrodes and a dielectric substance intervening between the two electrodes, one of the electrodes is composed of sintered niobium nitride. Preferably, the dielectric substance is composed of niobium oxide and the electrode other than the electrode composed of sintered niobium nitride is composed of an ingredient selected from electrolytes, organic semiconductors and inorganic semiconductors. This capacitor has good environmental stability and good leak current characteristics.

Abstract: The invention provides an effective and efficient method of making a hexammine cobaltic salt, such as hexammine cobaltic nitrate, in a consistent fashion through the control of one or more selected parameters of manufacture. Specific parameters considered and evaluated as a part of the invention included: order of addition of reactants, reaction temperature, oxidation, air or oxidant flow, catalyst content, and amount of ammonia.

Abstract: A method of continuously producing a non-oxide ceramic formed of a metal constituent and a non-metal constituent. A salt of the metal constituent and a compound of the non-metal constituent and a compound of the non-metal constituent are introduced into a liquid alkali metal or a liquid alkaline earth metal or mixtures to react the constituents substantially submerged in the liquid metal to form ceramic particles. The liquid metal is present in excess of the stoichiometric amount necessary to convert the constituents into ceramic particles to absorb the heat of reaction to maintain the temperature of the ceramic particles below the sintering temperature. Ceramic particles made by the method are part of the invention.

Abstract: Polycrystalline gallium nitride (GaN) characterized by having the atomic fraction of gallium ranging from between about 49% to 55%, an apparent density of between about 5.5 and 6.1 g/cm3, and a Vickers hardness of above about 1 GPa. Polycrystalline GaN can be made by hot isostatic pressing (HIPing) at a temperature ranging from about 1150° C. to 1300° C. and a pressure ranging from between about 1 and 10 Kbar. Alternatively, polycrystalline GaN can be made by high pressure/high temperature (HP/HT) sintering at a temperature ranging from about 1200° to 1800° C. and a pressure ranging from about 5 to 80 Kbar.