Abstract: A method for making a metal-vanadium oxide product includes selecting a metal, the group Au, Ag, Cu and Pt, providing nanotubular vanadium oxide composed of vanadium oxide layers separated by templating molecules, and producing a product by ionic change of the nanotubular vanadium oxide with a solution of the salt of the metal. The salt is selected from the group AuCl3, Au(CN)3, AgNO3, AgC2H3O2, HgClO3, AgF, PtCl4, Ptl4, and H2PtCl6. The selected metal can be in the form of nanometer-sized particles.

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: This invention relates to a process for preparing zirconium oxide, in its various forms, including zirconium-based mixed oxides. There is described a process for preparing a zirconium oxide in the absence of a cerium salt which comprises precipitating a zirconium hydroxide from an aqueous solution of a zirconium salt by reaction with an alkali in the presence of a controlled amount of sulphate anions at a temperature not greater than 50° C. and then calcining the hydroxide to form an oxide, wherein the oxide thus formed is essentially sulphate free. Catalysts and ceramics can be produced from the product oxides having improved thermal stability and improved sinterability, respectively. A particular use of the product oxide is as a promoter or catalyst support in automobile exhaust systems.

Abstract: There is provided a novel thermal barrier coating material which does not have a problem of phase transition, whose melting point is higher than its working temperature range, whose thermal conductivity is smaller than that of zirconia, and whose thermal expansion coefficient is greater than that of zirconia. The thermal barrier coating material comprises as a main component, a composition having an orthorhombic or monoclinic structure derived from perovskite (for example, a tabular perovskite structure expressed by the composition formula A2B2O7), or a tetragonal layer structure having a c axis/a axis ratio equal to or greater than 3 (for example, a K2NiF4 structure, a Sr3Ti2O7 structure, or a Sr4Ti3O10 structure), a composition expressed by the composition formula LaTaO4, or a composition having an olivine type structure expressed by the composition formula M2SiO4 or (MM?)2SiO4 (where M, M? are divalent metal elements).

Abstract: A niobium suboxide powder comprising 100 to 600 ppm of magnesium is described. The niobium suboxide powder may (alternatively or in addition to 100 to 600 ppm of magnesium) further include 50 to 400 ppm of molybdenum and/or tungsten. The niobium suboxide powder is suitable for the production of: capacitors having an insulator layer of niobium pentoxide; capacitor anodes produced from the niobium suboxide powder; and corresponding capacitors.

Abstract: Disclosed is a method of growing a single crystal from a melt contained in a crucible. The method includes the step of making the temperature of a melt increase gradually to a maximum point and then decrease gradually along the axis parallel to the lengthwise direction of the single crystal from the interface of the single crystal and the melt to the bottom of the crucible. The increasing temperature of the melt is kept to preferably have a greater temperature gradient than the decreasing temperature thereof. Preferably, the axis is set to pass through the center of the single crystal. Preferably, the convection of the inner region of the melt is made smaller than that of the outer region thereof.

Abstract: A composition, containing vanadium and a support, wherein at least a portion of the vanadium has crystallite sizes of less than about 100 ? as determined by an analytical method such as X-Ray Diffraction, is disclosed. A method of preparing such composition is also disclosed. The composition is employed in a process to remove a heavy metal from a gaseous feed stream which can optionally include a separate mercury adsorption stage.

Abstract: A particulate material is ground more efficiently using a mixture of at least two different sizes of yttrium-stabilized zirconia balls. The method facilitates preparation of photocatalysts with high activity.

Abstract: A crystallographically-oriented ceramic including first regions, in which crystal nuclei remain and which contain a specific element in a predetermined concentration range and extend at least partially in a layered shape along a crystal plane, and second regions, which contain the specific element in a different concentration range from the first regions and extend at least partially in a layered shape along the crystal plane. The regions are alternately repeated, and a compositional distribution exists in a direction orthogonal to the crystal plane. In the first region, the concentration of Na is higher, the concentration of K is lower, the concentration of Nb is lower, and the concentration of Ta is higher than the second region, and in the second region, the concentration of Na is lower, the concentration of K is higher, the concentration of Nb is higher, and the concentration of Ta is lower than the first region.

Abstract: Grain oriented ceramics constituted of a polycrystalline body having a first perovskite-type alkali-pentavalent metal oxide compound as the main phase, in which a specific crystal plane of each grain constituting the polycrystalline body is oriented. The grain oriented ceramics are obtained by molding a mixture of a first anisotropically-shaped powder A of which developed plane has a lattice matching with a specific crystal plane of the first perovskite-type alkali-pentavalent metal oxide compound and a first reaction material capable of reacting with the first anisotropically-shaped powder A thereby forming at least the first perovskite-type alkali-pentavalent metal oxide compound such that the first anisotropically-shaped powder A is oriented, and by heating them.

Abstract: The present invention comprises a method for preparing a mixed oxide catalyst for use in producing acrylonitrile or methacrylonitrile from propane or isobutene by ammoxidation in a gaseous phase via methods of heating or calcining precursor solid mixture to obtain mixed metal oxide catalyst compositions that exhibit catalytic activity.

Abstract: In one embodiment, a ferroelectric material is processed by placing the material in an environment including metal vapor and heating the material to a temperature below the Curie temperature of the material. This allows the bulk conductivity of the ferroelectric material to be increased without substantially degrading its ferroelectric domain properties. In one embodiment, the ferroelectric material comprises lithium tantalate and the metal vapor comprises zinc.

Abstract: A potassium niobate deposited body in accordance with an embodiment of the invention includes an R-plane sapphire substrate, and a potassium niobate layer or a potassium niobate solid solution layer formed above the R-plane sapphire substrate, wherein the potassium niobate layer or the potassium niobate solid solution layer epitaxially grows in a (100) orientation in a pseudo cubic system expression, and the potassium niobate layer or the potassium niobate solid solution layer has a (100) plane that tilts with a [11-20] direction vector as a rotation axis with respect to an R-plane (1-102) of the R-plane sapphire substrate.

Abstract: A mixture of zirconium hydroxides or zirconium basic carbonate with vanadium oxide (V205) co-reacts in high temperature aqueous slurry to form respectively an amorphous material, believed to be based on a zirconium analog of a zeolite structure, and a solid solution of zirconium oxide with vanadium oxide. The subject compositions, free of hexavalent chromium, are highly effective in providing blister-free corrosion prevention in typical coil and aerospace grade epoxy primer and color coat combinations.

Abstract: The present invention relates to compounds on apatite basis, having the general formula M5 (AO4)3X wherein X is situated in the hexagonal channels of the apatite structure and includes Cu-atoms, processes for the preparation thereof as well as applications of these compounds. The compounds presented herein are particularly useful as pigments.

Abstract: The method of preparing a negative active material for a non-aqueous electrolyte rechargeable battery includes mixing a vanadium compound and a lithium compound and then subjecting the mixture to first firing to obtain Li1.0(VxMy)1.0O2 having a layered halite type structure (where 0.5?x?1.0, 0?y?0.5, x+y=1, and M is selected from the group consisting of group 2 to 15 elements of the periodic table and combinations thereof); and adding a lithium compound to the Li1.0(VxMy)1.0O2 and then subjecting the resultant to second firing. The negative active material for a non-aqueous electrolyte rechargeable battery prepared according to the preparing method has high crystallinity, excellent charge and discharge characteristics at a high rate, and excellent charge and discharge cycle characteristics.

Abstract: Disclosed is metal composite oxides having the new crystal structure. Also disclosed are ionic conductors including the metal composite oxides and electrochemical devices comprising the ionic conductors. The metal composite oxides have an ion channel formed for easy movement of ions due to crystallographic specificity resulting from the ordering of metal ion sites and metal ion defects within the unit cell. Therefore, the metal composite oxides according to the present invention are useful in an electrochemical device requiring an ionic conductor or ionic conductivity.

Abstract: An object of the present invention is to provide: a catalyst for production of acrylic acid which catalyst is so high active as to give a still higher selectivity of acrylic acid (which is the objective product) or a long-catalytic-life-time catalyst for production of acrylic acid which catalyst is so high active as to be able to give a high acrylic acid yield while suppressing the temperature rise of the oxidation reaction to a low one; and processes for production of acrylic acid using these catalysts.

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: Metal-vanadium-oxide-product where the metal is Au, Ag or Pt and where the product is obtained by ion exchange of nanotubular vanadium oxide comprising vanadium oxide layers separated by templating molecules with a solution of a salt of the metal. Use of the metal-vanadium-oxide-product according to the invention as active cathode material in a battery. A process of producing of the metal-vanadium-oxide-product according to the invention. An active cathode material comprising a metal-vanadium-oxide-product according to the invention. A lithium battery comprising at least one lithium anode, at least one vanadium oxide cathode, an electrolyte and an adhesive layer bonding each of the anodes and the cathodes to the electrolyte, where the vanadium oxide cathode comprises a metal-vanadium-oxide-product according to the invention.

Abstract: A coating powder based on chemically modified titanium suboxides, for use in various coating techniques. Coatings produced from this powder are characterized by high electroconductivity, good solid lubricating properties and resistance to wear. For these reasons, there are numerous possibilities of use of components which were coated by suitable processes with this powder, especially as functional layers for fuel cells in electrochemical installations, in the new car industry, in mechanical engineering and in other economic activities. The coating powder based on titanium suboxides having a defined defect structure is characterized in that it is modified by at least one metallic alloying element and described by general formula: Tin-2Me2O2n-1.

Abstract: The present invention provides a process for making a complex metal oxide comprising the formula AxByOz. The process comprises the steps of: (a) reacting in solution at a temperature of between about 75° C. to about 100° C. at least one water-soluble salt of A, at least one water-soluble salt of B and a stoichiometric amount of a carbonate salt or a bicarbonate salt required to form a mole of a carbonate precipitate represented by the formula AxBy(CO3)n, wherein the reacting is conducted in a substantial absence of carbon dioxide to form the carbonate precipitate and wherein the molar amount of carbonate salt or bicarbonate salt is at least three times the stoichiometric amount of carbonate or bicarbonate salt required to form a mole of the carbonate precipitate; and (b) reacting the carbonate precipitate with an oxygen containing fluid under conditions to form the complex metal oxide.

Abstract: The product of a molten alkali metal metalate phase separation can be processed into a purified metal from a metal source. Metal sources include native ores, recycled metal, metal alloys, impure metal stock, recycle materials, etc. The method uses a molten alkali metal metalate as a process medium or solvent in purifying or extracting high value metal or metal oxides from metal sources. Vitrification methods using the silicate glass separation phase can be prepared as is or can be prepared with a particulate phase distributed throughout the silica glass phase and encapsulated and fixed within the continuous glass phase. Tungsten metal can be obtained from an alkali metal tungstate. A typically finely divided tungsten metal powder can be obtained from a variety of tungsten sources including recycled tungsten scrap, tungsten carbide scrap, low grade tungsten ore typically comprising tungsten oxide or other form of tungsten in a variety of oxidation states.

Abstract: A positive electrode active material for a nonaqueous electrolyte battery. The positive electrode active material has been manufactured through a mixing step and a heating step. In the mixing step, a mixture is produced by mixing niobium pentoxide (Nb2O5) with lithium hydroxide (LiOH) at a molar ratio of 1:1. In the heating step, the mixture is heated in an atmosphere of air at substantially 800° C. The positive electrode active material having been produced through the mixing process and the heating process causes the plateau potential in a discharge to be approximately 1.0 [V] for lithium. And the nonaqueous electrolyte battery using the positive electrode active material can operate at a voltage of approximately 1.0 [V].

Abstract: A method for manufacturing a potassium niobate deposited body includes: forming a buffer layer above a substrate composed of an R-plane sapphire substrate; forming above the buffer layer a potassium niobate layer or a potassium niobate solid solution layer that epitaxially grows in a (100) orientation in a pseudo cubic system expression; and forming an electrode layer above the potassium niobate layer or the potassium niobate solid solution layer, wherein a (100) plane of the potassium niobate layer or the potassium niobate solid solution layer is formed to tilt with a [11-20] direction vector as a rotation axis with respect to an R-plane (1-102) of the R-plane sapphire substrate.

Abstract: There is disclosed a method for manufacturing (Li, Na, K)(Nb, Ta)O3 type piezoelectric material in which a relative dielectric constant and an electric-field-induced strain can be improved. The method is a process in which a formed body of powder particles constituted of a composition of (Li, Na, K) (Nb, Ta)O3 is fired to produce the (Li, Na, K) (Nb, Ta)O3 type piezoelectric material, and a constant temperature is kept in a range of 850 to 1000° C. for a constant time in a heating process to a firing temperature.

Abstract: A nano-size lead-free piezoceramic powder and a method of mechanochemically synthesizing the same are provided. The nano-size lead-free piezoceramic powder can have a basic component of (KxNa1-x)NbO3, where x ranges from 0 to 1. A weight ratio of a milling ball to a raw powder can be set, and then the milling ball and the raw powder can be provided into a milling container at the set ratio. Nano-size lead-free piezoceramic powder can be mechanochemically synthesized using a high-energy ball mill device.

Abstract: The current invention relates to the preparation of an improved cathode active material for non-aqueous lithium electrochemical cell. In particular, the cathode active material comprised ?-phase silver vanadium oxide prepared by using silver- and vanadium-containing starting materials in a stoichiometric molar proportion to give a Ag:V ratio of about 1:2. The reactants are homogenized and then added to an aqueous solution followed by heating in a pressurized vessel. The resulting ?-phase SVO possesses a higher surface area than ?-phase SVO produced by other prior art techniques. Consequently, the ?-phase SVO material provides an advantage in greater discharge capacity in pulse dischargeable cells.

Abstract: Collections of particles comprising multiple a metal oxide can be formed with average particle sizes less than about 500 nm. In some embodiments, the particle collections have particle size distributions such that at least about 95 percent of the particles have a diameter greater than about 40 percent of the average diameter and less than about 160 percent of the average diameter. Also, in further embodiments, the particle collections have particle size distribution such that effectively no particles have a diameter greater than about four times the average diameter of the collection of particles.

Abstract: Methods of producing a safe and hygienic method for industrially and efficiently producing a perovskite-type composite oxide are provided that can maintain the catalytic activity of a noble metal at a high level. Methods include preparing a precursor of the perovskite-type composite oxide by mixing organometal salts of elementary components of the perovskite-type composite oxide and heat treating the precursor. The precursor may be prepared by mixing all elementary components constituting the perovskite-type composite oxide, or by mixing one or more organometal salts of part of the elementary components with the other elementary components prepared as alkoxides, a coprecipitate of salts, or a citrate complex of the respective elements.

Abstract: A niobium suboxide powder comprising 100 to 600 ppm of magnesium is described. The niobium suboxide powder may (alternatively or in addition to 100 to 600 ppm of magnesium) further include 50 to 400 ppm of molybdenum and/or tungsten. The niobium suboxide powder is suitable for the production of: capacitors having an insulator layer of niobium pentoxide; capacitor anodes produced from the niobium suboxide powder; and corresponding capacitors.

Abstract: Methods and apparatus for preconditioning a lithium niobate or lithium tantalate crystal. At least a portion of a surface of the crystal is covered with a condensed material including one or more active chemicals. The crystal is heated in a non-oxidizing environment above an activating temperature at which the active chemicals contribute to reducing the crystal beneath the covered surface portion. The crystal is cooled from above the activating temperature to below a quenching temperature at which the active chemicals become essentially inactive for reducing the crystal.

Abstract: An anode in a Direct Carbon Fuel Cell (DCFC) operating in a temperature range between 500 and 1200 degrees Celsius is provided. The anode material has high catalytic activity and selectivity for carbon oxidation, sufficient oxygen non-stoichiometry, rapid oxygen chemical diffusion, wide thermodynamic stability window to withstand reducing environment, sufficient electronic conductivity and tolerance to sulfur and CO2 environments. The anode has doped ruthenate compositions A1?xA?xRuO3, AB1?yRuyO3, or A1?xA?xB1?yRuyO3. A and A? may be divalent, trivalent, or tetravalent cation, and B is a multivalent cation. A is among lanthanide series elements La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er or Yb, and dopant A? is from Group IIA, IIIB, or IVB elements. The doped ruthenates can also be a (AB1?yRuyO3) structure or an ordered Ruddlesden-Popper series ((A1?xAx?)n+1(B1?yRuy)nO3n+1) structure where n=1 or 2. The dopant B is among Group IVB, VB, VIB, VIII, IB, and IIB elements.

Abstract: Method for producing metal oxide nanoparticles. The method includes generating an aerosol of solid metallic microparticles, generating plasma with a plasma hot zone at a temperature sufficiently high to vaporize the microparticles into metal vapor, and directing the aerosol into the hot zone of the plasma. The microparticles vaporize in the hot zone into metal vapor. The metal vapor is directed away from the hot zone and into the cooler plasma afterglow where it oxidizes, cools and condenses to form solid metal oxide nanoparticles.

Abstract: According to some embodiments, a pre-poled, single-domain body of a ferroelectric crystalline material such as lithium tantalate or lithium niobate is electrically reduced by applying a voltage across the body in a non-oxidizing environment while the body is heated to a process temperature below its Curie temperature. The voltage generates an electric field along the polar axis of the body. Electrodes may be formed on the body surface by applying an acetate-based silver paint.

Abstract: The present invention relates to a method for preparing an electroactive metal polyanion or a mixed metal polyanion comprising forming a slurry comprising a polymeric material, a solvent, a polyanion source or alkali metal polyanion source and at least one metal ion source; heating said slurry at a temperature and for a time sufficient to remove the solvent and form an essentially dried mixture; and heating said mixture at a temperature and for a time sufficient to produce an electroactive metal polyanion or electroactive mixed metal polyanion.

Abstract: A method for preparation for mesoporous oxide comprising a non silica oxide having a hexagonal pore structure periodicity and an average maximum pore length of from 2 nm to 5 nm, characterized by comprising blending 0.003 mol to 0.01 mol of TaCl5, NbCl5 or a mixture thereof and Al isopropoxide comprising 10 g of an aliphatic linear alcohol and 1 g of a template compound to prepare a mixture for forming a sol solution, adding 5 mol to 35 mol (based on the metal compounds) of water or an aqueous inorganic acid solution to the mixture followed by hydrolysis and polycondensation to give a sol solution, transferring the sol into an oxygen containing atmosphere followed by again at 40° C. to 100° C. to form a gel, and then calcinating the gel in an oxygen containing atmosphere at 350° C. to 550° C.; and the mesoporous oxide obtained by the method.

Abstract: Collections of particles comprising multiple a metal oxide can be formed with average particle sizes less than about 500 nm. In some embodiments, the particle collections have particle size distributions such that at least about 95 percent of the particles have a diameter greater than about 40 percent of the average diameter and less than about 160 percent of the average diameter. Also, in further embodiments, the particle collections have particle size distribution such that effectively no particles have a diameter greater than about four times the average diameter of the collection of particles.

Abstract: A method of manufacturing a complex metal oxide powder, the method including: preparing a raw material composition for forming a complex metal oxide; mixing an oxidizing solution including an oxidizing substance into the raw material composition to produce complex metal oxide particles to obtain a liquid dispersion of the particles; and separating the particles from the liquid dispersion to obtain a complex metal oxide powder. The complex metal oxide is shown by a general formula AB1-xCxO3, an element A including at least Pb, an element B including at least one of Zr, Ti, V, W, and Hf, and an element C including at least one of Nb and Ta.

Abstract: A meso porous transition metal oxide comprising one or more transition metal oxides, wherein the metal is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Cd, In, Sn, Sb, Hf, Ta, W and Re, and the pore wall of the meso pore thereof has a crystalline structure; and a method for preparing the meso porous transition metal oxide, characterized as comprising a step of carrying out a secondary calcination at 600-800° C. for 10 minutes to 10 hours.

Abstract: A process for producing powders of metal compound containing oxygen including the steps of: feeding at least one material selected from a liquid material and a solution material obtained by dissolving solid ingredient in organic solvent via a liquid flow controller into a vaporizer; vaporizing the materials in the vaporizer; adding oxygen; heating; cooling; and crystallizing. Also disclosed is the product formed by this process, and apparatus used in performing the process. The process and the apparatus enable easily mass-producing fine powders of metal compound containing oxygen used as materials for optical crystals, nonlinear crystals or magneto-optical crystals with reasonable production cost.

Abstract: A method for carrying out solid state reactions under reducing conditions is provided. Solid state reactants include at least one inorganic metal compound and a source of reducing carbon. The reaction may be carried out in a reducing atmosphere in the presence of reducing carbon. Reducing carbon may be supplied by elemental carbon, by an organic material, or by mixtures. The organic material is one that can form decomposition products containing carbon in a form capable of acting as a reductant. The reaction proceeds without significant covalent incorporation of organic material into the reaction product. In a preferred embodiment, the solid state reactants also include an alkali metal compound. The products of the method find use in lithium ion batteries as cathode active materials. Preferred active materials include lithium-transition metal phosphates and lithium-transition metal oxides.

Abstract: To provide a process for producing a lithium-cobalt composite oxide for a positive electrode of a lithium secondary battery excellent in volume capacity density, safety, charge and discharge cyclic durability, press density and productivity, by using in expensive cobalt hydroxide and lithium carbonate. A mixture having a cobalt hydroxide powder and a lithium carbonate powder mixed so that the atomic ratio of lithium/cobalt would be from 0.98 to 1.01, is fired in an oxygen-containing atmosphere at from 250 to 700° C., and the fired product is further fired in an oxygen-containing atmosphere at from 850 to 1,050° C., or such a mixture is heated at a temperature-raising rate of at most 4° C./min in a range from 250 to 600° C. and fired in an oxygen-containing atmosphere at from 850 to 1,050° C.

Abstract: This invention provides a piezoelectric ceramic composition that does not contain lead, can be sintered at a normal pressure and is excellent in at least one of a piezoelectric constant, an electro-mechanical coupling coefficient, a dielectric loss, a relative dielectric constant and a Curie point, its production method, and a piezoelectric device and a dielectric device each utilizing the piezoelectric ceramic composition. The invention relates to a piezoelectric composition expressed by the general formula {Lix(K1?yNay)1?x}(Nb1?zSbz)O3, each of x, y and z respectively falling within composition ranges of 0?x?0.2, 0?y?1.0 and 0?z?0.2 (with the exception of x=z=0), and its production method. The invention further relates to a piezoelectric device having a piezoelectric body formed of the piezoelectric ceramic composition described above and a dielectric device having a dielectric body formed of the piezoelectric ceramic composition described above.

Abstract: Improved solid acid electrolyte materials, methods of synthesizing such materials, and electrochemical devices incorporating such materials are provided. The stable electrolyte material comprises a solid acid in a eulytine structure capable of undergoing rotational disorder of oxyanion groups and capable of extended operation at elevated temperatures, that is, solid acids having hydrogen bonded anion groups; a superprotonic disordered phase; and capable of operating at temperatures of ˜100° C. and higher.

Abstract: The present invention relates to novel, water-soluble niobium compounds, a process for their preparation and their formulations.

Abstract: Nanoparticles comprising titanium, such as nanoscale doped titanium metal compounds, inorganic titanium compounds, and organic titanium compounds, their methods of manufacture, and methods of preparation of products from nanoparticles comprising titanium are provided.

Abstract: The present invention is the method for preparation of transition metal oxide having micro-mesoporous structure whose average fine pores size is not less than 1 nm and not more than 2 nm comprising, adding and dissolving transition metal salt which is a precursor of transition metal oxide and/or metal alkoxide in the solution prepared by dissolving polymer surfactant in organic solvent, hydrolyzing said transition metal salt and/or metal alkoxide and preparing sol solution which is polymerized and self organized, then obtaining gel whose organization is stabilized from said sol solution and removing said polymer surfactant by using water of room temperature or water to which alkali metal or alkaline earth metal ion is added.

Abstract: An object of the present invention is to provide a method for purifying a highly pure niobium compound and/or tantalum compound, the method enabling the purification of a highly pure niobium compound and tantalum compound in a simplified manner at a low cost. The object is met by providing a method comprising adding an organic solvent to an aqueous solution containing a niobium compound and/or tantalum compound together with impurities, and then performing extraction via the solution. A niobium compound and/or tantalum compound dissolved in a solution is allowed to precipitate, and said aqueous solution is obtained by dissolving the precipitate in water.

Abstract: The present invention is directed to lanthanide vanadate crystals having the formula LnVO4, wherein Ln is selected from La, Nd, Ce, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, and combinations of at least two thereof, made by a hydrothermal method for a wide variety of end-use applications. The present method requires reacting a source of Ln3+ ions and a source of VO43+ ions, wherein Ln is selected from the group consisting of La, Nd, Ce, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y and combinations of at least two thereof, in an aqueous solution at a temperature of from about 350° C. to about 600° C. and at a pressure of from about 8 kpsi to about 40 kpsi, the aqueous solution comprising hydroxide ions at a concentration of from about 0.01 to about 5 molarity. Specifically, when made by the present hydrothermal method, single crystals of sufficient size for use in a variety of optical applications are readily formed.