Abstract: Described herein are hollow nanocrystals having various shapes that can be produced by a simple chemical process. The hollow nanocrystals described herein may have a shell as thin as 0.5 nm and outside diameters that can be controlled by the process of making.

Abstract: The method produces low-stress, large-volume crystals with low birefringence and uniform index of refraction. The method includes growing the crystal with larger than desired dimensions including diameter and height from a melt; cooling and tempering the crystal with the larger than desired dimensions and after the cooling and tempering removing edge regions of the crystal with the larger than desired dimensions so that a diameter reduction and a height reduction of at least five percent occurs respectively and so that the crystal has the desired dimensions of diameter and height. No further tempering takes place after removing of the edge regions.

Abstract: Silicon wafers in the entire volume of which crystal lattice vacancies are the prevalent point defect type, have a rotationally symmetric region whose width is at least 80% of the wafer radius, crystal lattice vacancy agglomerates of at least 30 nm in a density ?6·103 cm?3, crystal lattice vacancy agglomerates of from 10 nm to 30 nm in a density of 1·105 cm?3 to 3·107 cm?3, OSF seeds in a density of 0 to 10 cm?2, and an average bulk BMD density of 5·108 cm?3 to 5·109 cm?3, which varies at most by a factor of 10 radially over the entire silicon wafer, and a BMD-free layer on the front side, wherein the first BMD is found at a depth of at least 5 ?m and on average at a depth of at least 8 ?m.

Abstract: Techniques for the formation of a silicon ingot using a low-grade silicon feedstock include forming within a crucible device a molten silicon from a low-grade silicon feedstock and performing a directional solidification of the molten silicon to form a silicon ingot within the crucible device. The directional solidification forms a generally solidified quantity of silicon and a generally molten quantity of silicon. The method and system include removing from the crucible device at least a portion of the generally molten quantity of silicon while retaining within the crucible device the generally solidified quantity of silicon. Controlling the directional solidification of the generally solidified quantity of silicon, while removing the more contaminated molten silicon, results in a silicon ingot possessing a generally higher grade of silicon than the low-grade silicon feedstock.

Abstract: The present invention provides a self-supporting substrate obtained by the steps of: forming an Al-based group-III nitride thin-layer having a thickness in the range of 3-200 nm on a base substrate made of a single crystal of an inorganic substance which substantially does not decompose at 800° C. in an inert gas atmosphere and which does produce volatiles by decomposition when contacting with a reducing gas in a temperature range of 800-1600° C., for example sapphire; forming voids along the interface between the base substrate and the Al-based group-III nitride thin-layer of the obtained laminated substrate by thermally treating the laminated substrate in a temperature range of 800-1600° C. in a reducing gas atmosphere containing ammonia gas; forming a group-III nitride single crystal thick-layer on the Al-based group-III nitride thin-layer; and separating these formed layers.

Abstract: A silicon carbide bulk single crystal is produced at a growth temperature of up to 2200° C. by sublimation growth and is subjected to thermal aftertreatment after the sublimation growth. The bulk single crystal is brought to an aftertreatment temperature that is higher than a growth temperature. Very low-stress and low-dislocation SiC substrates can be produced from such a SiC bulk single crystal, the substrates additionally having a particularly low electrical resistivity. The SiC bulk single crystal is positioned within an SiC powder before the thermal aftertreatment and it is completely surrounded by the SiC powder during the thermal aftertreatment.

Abstract: The present invention is related to a process for obtaining a larger area substrate of mono-crystalline gallium-containing nitride by making selective crystallization of gallium containing nitride on a smaller seed under a crystallization temperature and/or pressure from a supercritical ammonia-containing solution made by dissolution of gallium-containing feedstock in a supercritical ammonia-containing solvent with alkali metal ions, comprising: providing two or more elementary seeds, and making selective crystallization on the two or more separate elementary seeds to get a merged larger compound seed. The merged larger compound seed is used for a seed in a new growth process and then to get a larger substrate of mono-crystal gallium-containing nitride.

Abstract: A method for forming an object, including providing at least a first material having a melting point at a first temperature and a second material having a melting point at a second temperature; heating at least a portion of the first and second materials above the first and second temperatures to form a substantially molten alloy, the molten alloy having a solidifying point at a third temperature, the third temperature being less than the first temperature and the second temperature; and providing substantially solid further material to at least a portion of the molten alloy, the further material having a melting point at a temperature greater than the third temperature.

Abstract: A process for the detection of polymorphic or pseudopolymorphic forms of solid, molecular and crystallizing compounds, or of molecular, cocrystalline compounds or of solid solutions which consist of at least two solid, molecular and crystallizing compounds, in a series investigation using an apparatus for parallel investigations in vessels of an array under different conditions in each vessel, in which substantially only the amorphous form of the crystallizing compound, a solvate of the crystallizing compound or substantially only the amorphous form or a solvate of a compound in a mixture of at least two compounds is used as a suspension or solution, the solutions of amorphous compound having, at the same temperature, a higher content of crystallizable compounds than is achievable with a corresponding crystalline compound.

Abstract: An apparatus for growing a synthetic diamond comprises a growth chamber, at least one manifold allowing access to the growth chamber, and a plurality of safety clamps positioned on opposite sides of the growth chamber; wherein the growth chamber and the plurality of safety clamps are comprised of a material having a tensile strength of about 120,000-200,000 psi, a yield strength of about 100,000-160,000 psi, an elongation of about 10-20%, an area reduction of about 40-50%, an impact strength of about 30-40 ft-lbs, and a hardness greater than 320 BHN.

Abstract: The present invention relates to a method for increasing the conversion of group III metal to group III nitride in a fused metal containing group III elements, with the introduction of nitrogen into the fused metal containing group III, at temperatures?1100° C. and at pressures of below 1×108 Pa, wherein a solvent adjunct is added to the fused metal containing group III elements, which is at least one element of the following elements C, Si, Ge, Fe, and/or at least one element of the rare earths, or an alloy or a compound of these elements, in particular their nitrides.

Abstract: A manufacturing method for quasi phase matching (QPM) wavelength converter elements using crystal quartz as a base material in which twins are periodically induced, comprises a step of periodically inducing the twins by applying a stress onto a crystal quartz substrate as the base material so that an angle ? of a direction in which the stress is applied relative to a Z axis of the crystal quartz is 60°<?<90°.

Abstract: The method is capable of producing a sapphire single crystal without forming cracks and without using an expensive crucible. The method comprises the steps of: putting a seed crystal and a raw material in a crucible; setting the crucible in a cylindrical heater; heating the crucible; and producing temperature gradient in the cylindrical heater so as to sequentially crystallize a melt. The crucible is composed of a material having a specific linear expansion coefficient which is capable of preventing mutual stress, which is caused by a difference between a linear expansion coefficient of the crucible and that of the sapphire single crystal in a direction perpendicular to a growth axis thereof, from generating in the crucible and the sapphire single crystal, or which is capable of preventing deformation of the crucible without generating a crystal defect caused by the mutual stress in the sapphire single crystal.

Abstract: In various embodiments, methods of forming single-crystal AlN include providing a substantially undoped polycrystalline AlN ceramic having an oxygen concentration less than approximately 100 ppm, forming a single-crystal bulk AlN crystal by a sublimation-recondensation process at a temperature greater than approximately 2000° C., and cooling the bulk AlN crystal to a first temperature between approximately 1500° C. and approximately 1800° C. at a first rate less than approximately 250° C./hour.

Abstract: A method of introducing NV centres in single crystal CVD diamond material is described. One step of the method comprises irradiating diamond material that contains single substitutional nitrogen to introduce isolated vacancies into the diamond material in a concentration of at least 0.05 ppm and at most 1 ppm. Another step of the method comprises annealing the irradiated diamond to form NV centres from at least some of the single substitutional nitrogen defects and the introduced isolated vacancies.

Abstract: The invention is related to a method of obtaining bulk mono-crystalline gallium-containing nitride, comprising a step of seeded crystallization of mono-crystalline gallium-containing nitride from supercritical ammonia-containing solution, containing ions of Group I metals and ions of acceptor dopant, wherein at process conditions the molar ratio of acceptor dopant ions to supercritical ammonia-containing solvent is at least 0.0001. According to said method, after said step of seeded crystallization the method further comprises a step of annealing said nitride at the temperature between 950° C. and 1200° C., preferably between 950° C. and 1150° C. The invention covers also bulk mono-crystalline gallium-containing nitride, obtainable by the inventive method. The invention further relates to substrates for epitaxy made of mono-crystalline gallium-containing nitride and devices manufactured on such substrates.

Abstract: A method of epitaxial growth of a 4H—SiC single crystal enabling growth of an SiC single crystal with low defects and low impurities able to be used for a semiconductor material at a practical growth rate, comprising growing a 4H—SiC single crystal on a 4H—SiC single crystal substrate by epitaxial growth while inclining an epitaxial growth plane of the substrate from a (0001) plane of the 4H—SiC single crystal by an off-angle of at least 12 degrees and less than 30 degrees in a <11-20> axial direction, and a 4H—SiC single crystal obtained by the same.

Abstract: High temperature composites and thermal barrier coatings, and related methods, using anisotropic ceramic materials, such materials as can be modified to reduce substrate thermal mismatch.

Abstract: A method for the treatment of a crystal, such as a lithium niobate crystal or lithium tantalate crystal, having nonlinear optical properties. The crystal comprises foreign atoms which bring about specific absorption of radiated light. The foreign atoms are transformed into a lower valent state by means of oxidation. Electrons, which are released during oxidation, are discharged from the crystal with the aid of an external power source.

Abstract: A silicon wafer having no epitaxially deposited layer or layer produced by joining to the silicon wafer, with a nitrogen concentration of 1·1013-8·1014 atoms/cm3, an oxygen concentration of 5.2·1017-7.5·1017 atoms/cm3, a central thickness BMD density of 3·108-2·1010 cm?3, a cumulative length of linear slippages ?3 cm and a cumulative area of areal slippage regions ?7 cm2, the front surface having <45 nitrogen-induced defects of >0.13 ?m LSE in the DNN channel, a layer at least 5 ?m thick, in which ?1·104 COPs/cm3 with a size of ?0.09 ?m occur, and a BMD-free layer ?5 ?m thick. Such wafers may be produced by heat treating the silicon wafer, resting on a substrate holder, a specific substrate holder used depending on the wafer doping. For each holder, maximum heating rates are selected to avoid formation of slippages.

Abstract: A method for manufacturing a silicon wafer includes a step of annealing a silicon wafer which is sliced from a silicon single crystal ingot, thereby forming a DZ layer in a first surface and in a second surface of the silicon wafer and a step of removing either a portion of the DZ layer in the first surface or a portion of the DZ layer in the second surface.

Abstract: A suspension of particles is rapidly self-assembled with a minimal number of defects into a three-dimensional array of particles onto a substrate under simultaneous sedimentating and annealing forces. This array of particles may be ordered as an opal structure. Optionally, the synthesized structure may incorporate an electrolyte into the suspension and be used as a sacrificial form for micromoulding an inverse structure. The inverse structure may exhibit a photonic band gap. Optionally, necking and material composition may be adjusted after micromoulding. These structures are useful to a wide variety of applications. The photonic band gap structure may be heated to function as a light source. The light source may be fitted into standard sockets.

Abstract: A layered semiconductor wafer contains the following layers in the given order: a monocrystalline substrate wafer (1) containing substantially silicon, a first amorphous intermediate layer (2) of an electrically insulating material having a thickness of 2 nm to 100 nm, a monocrystalline first oxide layer (3) having a cubic Ia-3 crystal structure, a composition of (M12O3)1-x(M22O3)x wherein each of M1 and M2 is a metal and wherein 0?x?1, and a lattice constant which differs from the lattice constant of the material of the substrate wafer by 0% to 5%. The invention also relates to a process for manufacturing such semiconductor wafers by epitaxial deposition.

Abstract: An epitaxial substrate including a single-crystal base material and an upper layer of a group III nitride crystal film which is epitaxially formed on a main surface of the base material undergoes heating treatment in a nitrogen atmosphere at 1950° C. or higher for one minute. The result showed that, while a ?-ALON layer was formed only at the interface between the base material and the upper layer, the dislocation density in the group III nitride crystal was reduced to one tenth or less of the dislocation density before the heating treatment. The result also showed that the surface of the epitaxial substrate after the heating treatment had a reduced number of pits, which confirmed that high-temperature and short-time heating treatment was effective at improving the crystal quality and surface flatness of the group III nitride crystal.

Abstract: The present invention comprises methods and apparatuses for the production or formation of co-crystals. The methods and apparatuses can be used to grind two or more co-crystal components resulting in the formation of co-crystals. The resultant co-crystals can have several uses as disclosed herein.

Abstract: A method of fabricating an SiC single crystal includes (a) physical vapor transport (PVT) growing a SiC single crystal on a seed crystal in the presence of a temperature gradient, wherein an early-to-grow portion of the SiC single crystal is at a lower temperature than a later-to-grow portion of the SiC single crystal. Once grown, the SiC single crystal is annealed in the presence of a reverse temperature gradient, wherein the later-to-grow portion of the SiC single crystal is at a lower temperature than the early-to-grow portion of the SiC single crystal.

Abstract: A method of subjecting a silicon wafer doped with boron to a heat treatment in an argon atmosphere, wherein the argon atmosphere is replaced with a hydrogen atmosphere or a mixed gas of an argon gas and a hydrogen gas in a proper fashion, to thereby uniformize a boron concentration in the thickness direction of the surface layer of the silicon wafer doped with boron.

Abstract: A method for manufacturing Group III nitride crystals with high quality is provided. By the method, a crystal raw material solution and gas containing nitrogen are introduced into a reactor vessel, which is heated, and crystals are grown in an atmosphere of pressure applied thereto. The gas is introduced from a gas supplying device to the reactor vessel through a gas inlet of the reactor vessel, and then is exhausted to the inside of a pressure-resistant vessel through a gas outlet of the reactor vessel. Since the gas is introduced directly to the reactor vessel, impurities attached to the pressure-resistant vessel and the like into the crystal growing site can be prevented. Further, the gas flows through the reactor vessel, to suppress aggregation of an evaporating alkali metal, etc., at the gas inlet and reduce flow of the metal vapor into the gas supplying device.

Abstract: A method of manufacturing calcium fluoride single crystal includes cooling the calcium fluoride single crystal with variable cooling rates so that throughout a temperature range in the cooling step, maximum shear stress inside the calcium fluoride single crystal caused by thermal stress is approximately equal to or smaller than critical resolved shear stress (?c) of the calcium fluoride single crystal in a <1 1 0> direction on a {0 0 1} plane of the calcium fluoride single crystal, and is maintained to be an approximately constant ratio, and adding strontium fluoride when growing the single crystal before the cooling step.

Abstract: A beryllium borate fluoride salt nonlinear optical crystal is represented by molecule formula Mbe2BO3F2, wherein M is Rb or Cs. The crystal is grown by melt salt method, comprising the following step, mixing beryllium borate fluoride salt with flux at appropriate ratio, rising to 750-800° C., and keeping at constant temperature, then cooling to 2-10° C. higher than saturated temperature to obtain a elevated solution; putting seed crystal on seed crystal pole into the elevated solution, rotating the seed crystal pole, cooling to saturated temperature, and then cooling slowly; raising the obtained crystal above liquid level and cooling to room temperature, then obtaining the present nonlinear optical crystal. The crystal has nonlinear optical effect, broad transmittance wave, adsorption edge of ultraviolet lower to 150 nm, doesn't deliquesce, isn't soluble to diluted hydrochloric acid and nitric acid, and has good chemical resistance.

Abstract: By using a two-step RTP (rapid thermal processing) process, the wafer is provided which has an ideal semiconductor device region secured by controlling fine oxygen precipitates and OiSFs (Oxidation Induced Stacking Fault) located on the surface region of the wafer. By performing the disclosed two-step rapid thermal process, the distribution of defects can be accurately controlled and an ideal device active zone can be formed up to a certain distance from the surfaces of the wafer. In addition, it is possible to maximize the internal gettering (IG) efficiency by enabling the oxygen precipitates and the bulk stacking faults to have constant densities in the depth direction in an internal region of the wafer, that is, the bulk region. In order to obtain the constant concentration profile of the oxygen precipitates and the bulk stacking faults in the bulk region, the wafer is subjected to the aforementioned two-step rapid thermal process in a predetermined mixed gas atmosphere.

Abstract: A method for growing a silicon single crystal having a hydrogen defect density of equal to or less than 0.003 pieces/cm2 using a Czochralski method, includes: a crystal growth step performed in an atmospheric gas containing a hydrogen-containing gas so as to allow hydrogen gas to have a partial pressure of equal to or higher than 40 Pa and equal to or lower than 400 Pa; and a cooling state control step of setting the amount of time in a hydrogen aggregation temperature range which is a range of equal to or lower than 850° C. and equal to or higher than 550° C. to be equal to or longer than 100 minutes and equal to or shorter than 480 minutes.

Abstract: The invention relates to a method for re-crystallization of layer structures by means of zone melting, in which, as a result of convenient arrangement of a plurality of heat sources, a significant acceleration of the zone melting method can be achieved. The method is based on the fact that a continuous recrystallisation of the layer is ensured as a result of overlaps being produced. According to the invention, a device is likewise provided with which the method according to the invention can be achieved. The method according to the invention is used in particular in the production of crystalline silicon thin layer solar cells or for example in SOI technology. However the application likewise relates also in general to the processing of metals, plastic materials or adhesives and here in particular to the production of thin layers.

Abstract: A controlled heat extraction system and method thereof is disclosed. In one embodiment, a system includes a housing to form a chamber. The system further includes a seed cooling component adapted to support a bottom of the crucible and to receive a coolant fluid to cool the supported portion of the crucible. The system also includes at least one heating element substantially surrounding the seed cooling component and the crucible to heat the crucible, where the seed cooling component along with the crucible is movable relative to the at least one heating element. Furthermore, the system includes an insulating element substantially surrounding the crucible, the seed cooling component and the at least one heating element. Additionally, the system includes a gradient control device (GCD) movable relative to the insulating element, the at least one heating element, the seed cooling component and the crucible over a range of positions.

Abstract: A temperature gradient is established in a crystallization crucible by means of a heat source and a cooling system. The cooling system comprises a heat exchanger and an adjustable additional heat source. The cooling system is preferably formed by an induction coil cooled by a coolant liquid circulating in the induction coil and by an electrically conductive induction susceptor positioned between the crucible and induction coil. The fabrication process comprises heating the crucible via the top and controlling heat extraction from the crucible downwards by means of the heat exchanger and by means of regulation of the adjustable additional heat source.

Abstract: A lithium tantalate substrate obtained by working in the state of a substrate a lithium tantalate crystal grown by the Czochralski method is buried in a mixed powder of Al and Al2O3, followed by heat treatment carried out at a temperature kept to from 350 to 600° C., to manufacture a lithium tantalate substrate having volume resistivity which has been controlled within the range of from more than 108 to less than 1010 ?cm. The substrate obtained has no pyroelectricity, and it can be made colored and opaque from a colorless and transparent state and also sufficiently has the properties required as a piezoelectric material.

Abstract: A scintillator single crystal of a specific cerium-doped silicate compound that contains 0.00005 to 0.1 wt % of one or more types of element selected from the group consisting of elements belonging to group 2 of the periodic table based on the total weight of the single crystal.

Abstract: Epitaxially coated semiconductor wafers are prepared by a process in which a semiconductor wafer polished at least on its front side is placed on a susceptor in a single-wafer epitaxy reactor and epitaxially coated on its polished front side at temperatures of 1000-1200° C., wherein, after coating, the semiconductor wafer is cooled in the temperature range from 1200° C. to 900° C. at a rate of less than 5° C. per second. In a second method for producing an epitaxially coated wafer, the wafer is placed on a susceptor in the epitaxy reactor and epitaxially coated on its polished front side at a deposition temperature of 1000-1200° C., and after coating, and while still at the deposition temperature, the wafer is raised for 1-60 seconds to break connections between susceptor and wafer produced by deposited semiconductor material before the wafer is cooled.

Abstract: The present invention relates to a large-sized and high-quality bismuth-zinc-borate (Bi.sub.2 ZnB.sub.2 O.sub.7) single crystal, preparation methods and applications thereof. The crystal has cross-sectional dimensions greater than one centimeter, a nonlinear optical effect of about 3-4 times that of KH.sub.2 PO.sub.4 (KDP), and an optical transmission wavelength range of 330-3300 nm. The crystal can be grown from a compound melt by a Czochralski method, a Kyropoulos method or a Bridgman method with the raw material being the synthetic compound Bi.sub.2 ZnB.sub.2 O.sub.7. Alternatively, the crystal may be grown from a high-temperature solution method by using Bi.sub.2 O.sub.3 as a flux. The crystal may be applied in nonlinear optical devices such as frequency doubling generators, frequency upconverters or downconverters, and optical parametric oscillators.

Abstract: A method of making a solar grade silicon wafer is disclosed. In at least some embodiments of this invention, the method includes the follow steps: providing a slurry including a liquid that essentially prevents the oxidation of silicon powder and a silicon powder that is essentially free of oxides; providing a solar grade wafer mold defining an interior for receiving the slurry; introducing the slurry into the solar grade wafer mold; precipitating the silicon powder from the slurry to form a preform of the solar grade silicon wafer; and crystallizing the preform to make the solar grade silicon wafer.

Abstract: Systems and methods are disclosed for crystal growth using VGF and VB growth processes to reduce body lineage. In one exemplary embodiment, there is provided a method of inserting an ampoule with raw material into a furnace having a heating source, growing a crystal using a vertical gradient freeze process wherein the crystallizing temperature gradient is moved relative to the crystal and/or furnace to melt the raw material and reform it as a monocrystalline compound, and growing the crystal using a vertical Bridgman process on the wherein the ampoule/heating source are moved relative each other to continue to melt the raw material and reform it as a monocrystalline compound.

Abstract: The invention relates to a process for manufacturing a single crystal comprising a rare-earth halide, having improved machining or cleavage behaviour, comprising heat treatment in a furnace, the atmosphere of which is brought, for at least 1 hour, to between 0.70 times Tm and 0.995 times Tm of a single crystal comprising a rare-earth halide, Tm representing the melting point of said single crystal, the temperature gradient at any point in the atmosphere of the furnace being less than 15 K/cm for said heat treatment. After carrying out the treatment according to the invention, the single crystals may be machined or cleaved without uncontrolled fracture. The single crystals may be used in a medical imaging device, especially a positron emission tomography system or a gamma camera or a CT scanner, for crude oil exploration, for detection and identification of fissile or radioactive materials, for nuclear and high-energy physics, for astrophysics or for industrial control.

Abstract: The inhomogeneous energy distribution at the beam spot on the irradiated surface is caused by a structural problem and processing accuracy of the cylindrical lens array forming an optical system. According to the present invention, in the optical system for forming a rectangular beam spot, an optical system for homogenizing the energy distribution of the shorter side direction of a rectangular beam spot of a laser light on an irradiated surface is replaced with a light guide. The light guide is a circuit that can confine emitted beams in a certain region and guide and transmit its energy flow in parallel with the axis of a path thereof.

Abstract: An LuAP scintillation detector and a method for improving the light output and uniformity of an LuAP scintillator crystal is provided, wherein the method includes disposing the scintillator crystal in a predetermined environment at a threshold temperature to generate an initial scintillator crystal, annealing the initial scintillator crystal in the predetermined environment at the threshold temperature to create an annealed scintillator crystal and cooling the annealed scintillator crystal in the predetermined environment to a final temperature.

Abstract: In order to obtain a thin-film transistor having high characteristics using a metal element for accelerating the crystallization of silicon, a nickel element is selectively added to the surface of an amorphous silicon film (103) in regions (101) and (102) and regions (108) to (110), and a heat treatment is carried out to grow crystals (horizontal growth) in directions parallel to the substrate as indicated by arrows (104) to (107). At this point, the regions (108) to (110) having a width of 5 ?m or less serve as stopper regions so that horizontal growth starting from the regions (101) and (102) stops there. In this way, the horizontal growth regions can be formed with high controllability. Then a circuit such as a shift register can be constructed with a region having the same crystal growth form.

Abstract: Scandium, yttrium, and lanthanide sesquioxide crystals having the formula Ln2O3, wherein Ln is selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, with or without an activator ion, are made by a hydrothermal method for a variety of end-use applications.

Abstract: An active layer side silicon wafer is heat-treated in an oxidizing atmosphere to thereby form a buried oxide film therein. The active layer side silicon wafer is then bonded to a supporting side wafer with said buried oxide film interposed therebetween thus to fabricate an SOI wafer. Said oxidizing heat treatment is carried out under a condition satisfying the following formula: [Oi]?2.123×1021exp(?1.035/k(T+273)), where, T is a temperature of the heat treatment, and [Oi] (atmos/cm3) is an interstitial oxygen concentration.

Abstract: A magnesium oxide single crystal having controlled crystallinity has a subboundary, and ranges of variation of diffraction line positions, as measured for reciprocal lattice maps with respect to a region surrounded by the same subboundary, with the range of the variation of 1×10?3 to 2×10?2 degree of on ?? coordinates, and with the range of the variation of 4×10?4 to 5×10?3 degree on 2? coordinates.

Abstract: An electrically conductive diamond electrode and process for preparation thereof is described. The electrode comprises diamond particles coated with electrically conductive doped diamond preferably by chemical vapor deposition which are held together with a binder. The electrodes are useful for oxidation reduction in gas, such as hydrogen generation by electrolysis.

Abstract: The present invention provides a single crystal heat treatment method, having a step of heating a single crystal of a cerium-doped silicate compound represented by any of general formulas (1) to (4) below in an oxygen-containing atmosphere Y2?(x+y)LnxCeySiO5??(1) (wherein Ln represents at least one elemental species selected from a group consisting of elements belonging to the rare earth elements, x represents a numerical value from 0 to 2, and y represents a numerical value greater than 0 but less than or equal to 0.2) Gd2?(z+w)LnzCewSiO5??(2) (wherein Ln represents at least one elemental species selected from a group consisting of elements belonging to the rare earth elements, z represents a numerical value greater than 0 but less than or equal to 2, and w represents a numerical value greater than 0 but less than or equal to 0.