Abstract: This zirconia powder contains 2.5 to 3.5 mol % of yttria; has a specific surface area of 5 to 20 m2/g; and has crystal phases that include a monoclinic crystal phase percentage of 20 to 40% and a tetragonal crystal phase percentage of 60 to 80%. When the zirconia powder is molded under a mold pressure of 0.8 t/cm2 and then sintered under a condition of 2 hours at 1450° C. to obtain a sintered body, the sintered body has crystal phases that include a monoclinic crystal phase percentage of 1 to 3%, a tetragonal crystal phase percentage of 77 to 94%, and a cubic crystal phase percentage of 5 to 20%.

Abstract: Provided is an alumina-based composite oxide having a large initial specific surface area and a small initial mean pore size, with excellent heat resistance of the specific surface area and pore volume; and a production method therefor. Specifically, provided is an alumina-based composite oxide wherein the initial crystallite diameter is 10 nm or less and the initial specific surface area is 80 m2/ml or more; after calcination at 1200° C. for 3 hours in air, the specific surface area is 10 m2/ml or more; the initial mean pore size is 10 nm or more and 50 nm or less; and after calcination at 1200° C. for 3 hours in air, the pore volume retention rate is 10% or more, which is determined by (P1/P0)×100 wherein P0 represents an initial pore volume (ml/g), and P1 represents a pore volume (ml/g) after calcination at 1200° C. for 3 hours in air.

Abstract: Provided is an alumina-based composite oxide having a large initial specific surface area and a small initial mean pore size, with excellent heat resistance of the specific surface area and pore volume; and a production method therefor. Specifically, provided is an alumina-based composite oxide wherein the initial crystallite diameter is 10 nm or less and the initial specific surface area is 80 m2/ml or more; after calcination at 1200° C. for 3 hours in air, the specific surface area is 10 m2/ml or more; the initial mean pore size is 10 nm or more and 50 nm or less; and after calcination at 1200° C. for 3 hours in air, the pore volume retention rate is 10% or more, which is determined by (P1/P0)×100 wherein P0 represents an initial pore volume (ml/g), and P1 represents a pore volume (ml/g) after calcination at 1200° C. for 3 hours in air.

Abstract: The present invention provides a zirconium-containing alcohol solution including zirconium oxyacetate, a C1-3 carboxylic acid or a C1-3 carboxylate, water, and an alcohol-based solvent, the zirconium-containing alcohol solution being such that the transmittance for light of a wavelength of 380 nm after heating for 50 hours at a temperature of 40° C. is 90-100%.

Abstract: A ceramic powder material which contains an LLZ-based garnet-type compound represented by Li7?3xAlxLa3Zr2O12 (where x satisfies 0?x?0.3) and in which a main phase of a crystal phase undergoes phase transition from a tetragonal phase to a cubic phase in the process of raising a temperature from 25° C. to 1050° C. and the main phase is the cubic phase even after the temperature is lowered to 25° C.

Abstract: In order to provide a zirconium boride that provides high caloric value at the time of its combustion with a compound having radicals such as perchlorate and can combust in a short period of time, while providing high physical stability, an amount of radical derived from lattice defect detected by ESR spectroscopy, is set to 0.1×1015 spin/mg or more.

Abstract: Provided is an alumina-based composite oxide having a large initial specific surface area and a small initial mean pore size, with excellent heat resistance of the specific surface area and pore volume; and a production method therefor. Specifically, provided is an alumina-based composite oxide wherein the initial crystallite diameter is 10 nm or less and the initial specific surface area is 80 m2/ml or more; after calcination at 1200° C. for 3 hours in air, the specific surface area is 10 m2/ml or more; the initial mean pore size is 10 nm or more and 50 nm or less; and after calcination at 1200° C. for 3 hours in air, the pore volume retention rate is 10% or more, which is determined by (P1/P0)×100 wherein P0 represents an initial pore volume (ml/g), and P1 represents a pore volume (ml/g) after calcination at 1200° C. for 3 hours in air.

Abstract: These surface-modified metal compound particles have metal compound particles the surfaces of which are modified by: at least one first carboxylic acid selected from the group consisting of a methacrylic acid, an acrylic acid, and a propionic acid; and at least one second carboxylic acid selected from the group consisting of a C6-C16 fatty acid and a C7-C32 monovalent carboxylic acid having at least one benzene ring, wherein at least a portion of the first carboxylic acid is a carboxylic acid type in which a hydrogen atom of the carboxy group is not dissociated as an ion.

Abstract: The present invention provides a scandia-stabilized zirconia powder for solid oxide fuel cells or a scandia-stabilized zirconia sintered body for solid oxide fuel cells, each having high crystal structure stability, low grain-boundary resistivity, and high ionic conductivity; and the production methods of these. The scandia-stabilized zirconia powder for solid oxide fuel cells comprises a compound represented by formula (1): (ZrO2)1-x-a(Sc2O3)x(Al2O3)a. In formula (1), 0.09?x?0.11 and 0.002?a<0.01 are satisfied. The scandia-stabilized zirconia powder has a rhombohedral phase crystal structure. The sintered body of the scandia-stabilized zirconia powder has a cubic phase crystal structure. The sintered body of the scandia-stabilized zirconia powder has a grain-boundary resistivity of 12 ?·cm or less at 550° C.

Abstract: Provided are surface-modified metal compound particles comprising metal compound particles which are surface-modified with one or more types of carboxylic acid selected from a methacrylic acid, an acrylic acid, and a propionic acid, and a 12-hydroxystearic acid, wherein a portion or all of the one or more types of carboxylic acid selected from a methacrylic acid, an acrylic acid, and a propionic acid is a carboxylic acid (protonated) type.

Abstract: Provided is a lithium-containing zirconium phosphate having excellent high-temperature resistance and mechanical strength, which is useful as a lithium-ion-conducting inorganic solid electrolyte material, and methods for producing a calcined powder and a sintered body thereof. Specifically, the lithium-containing zirconium phosphate is characterized in that (1) the lithium-containing zirconium phosphate has a compositional ratio of Li:M1:M2:P=1.0 to 1.7:0.10 to 0.35:2.0:more than 3.00 to 3.50 or less; (2) M1 contains at least one member selected from the group consisting of Ca, Mg, Sr, and Ba; when M1 contains two or more members, the ratio of M1 is 0.10 to 0.35 in total; and (3) M2 contains Zr alone, or contains Zr and at least one member selected from the group consisting of Al, Sc, Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, the ratio of Zr in M2 being 1.47 to 2.00.

Abstract: Provided is a zirconia powder that has excellent moldability and a high sintered density, and that can produce a zirconia sintered product in a simple manner; also provided is a method for producing the zirconia powder. The zirconia powder according to the present invention comprises 2 to 6 mol % of yttria, has a volume of pores with a pore diameter of 200 nm or less of 0.14 to 0.28 mL/g, and has a relative molding density of 44 to 55% when the zirconia powder is molded at a molding pressure of 1 t/cm2, wherein the relative molding density is represented by the following formula (1): relative molding density (%)=(molding density/theoretical sintered density)×100??(1).

Abstract: Provided is a zirconia powder that has excellent moldability and a high sintered density, and that can produce a zirconia sintered product in a simple manner; also provided is a method for producing the zirconia powder. The zirconia powder according to the present invention comprises 2 to 6 mol % of yttria, has a volume of pores with a pore diameter of 200 nm or less of 0.14 to 0.28 mL/g, and has a relative molding density of 44 to 55% when the zirconia powder is molded at a molding pressure of 1 t/cm2, wherein the relative molding density is represented by the following formula (1): relative molding density (%)=(molding density/theoretical sintered density)×100 ??(1).

Abstract: Provided is a cerium-zirconium-based composite oxide having an excellent OSC, high catalytic activity, and excellent heat resistance, and also provided is a method for producing the same. The cerium-zirconium-based composite oxide comprises cerium, zirconium, and a third element other than these elements. The third element is (a) a transition metal element or (b) at least one or more elements selected from the group consisting of rare earth elements and alkaline earth metal elements. After a heat treatment at 1,000° C. to 1,100° C. for 3 hours, (1) the composite oxide has a crystal structure containing a pyrochlore phase, (2) a value of {I111/(I111+I222)}×100 is 1 or more, and (3) the composite oxide has an oxygen storage capacity at 600° C. of 0.05 mmol/g or more, and an oxygen storage capacity at 750° C. of 0.3 mmol/g or more.

Abstract: This invention provides a zirconia-based porous body having a pore diameter suitable for supporting catalytic active species, such as precious metals, small variability in pore diameter, and a sufficient specific surface area even after 12-hour heating at 1000° C. Specifically, the invention provides a zirconia-based porous body in particle form having (1) a pore diameter peak at 20 to 100 nm in the pore distribution by BJH method, a P/W ratio of 0.05 or more wherein W represents half width of the peak and P represents height of the peak in the measured pore distribution curve, and a total pore volume of 0.5 cm3/g or more; and (2) a pore diameter peak at 20 to 100 nm, the P/W ratio of 0.03 or more, a specific surface area of at least 40 m2/g, and a total pore volume of 0.3 cm3/g or more, after heat treatment at 1000° C. for 12 hours.

Abstract: The present invention provides a zirconium oxide-titanium oxide composite sol comprising single nano-level, monodisperse, and amorphous zirconium oxide-titanium oxide composite nanoparticles. Specifically, the present invention provides a zirconium oxide-titanium oxide composite sol comprising zirconium oxide-titanium oxide composite nanoparticles dispersed in a dispersion medium; wherein the zirconium oxide-titanium oxide composite nanoparticles have a ZrO2/TiO2 composition ratio of 95/5 to 50/50, and a primary particle diameter of 10 nm or less, and the dispersion medium is a polar dispersion medium.

Abstract: A ZrO2—Al2O3-based ceramic sintered compact containing tetragonal ZrO2 particles having a crystallite size of from 5 to 20 nm as a main component and having an ?-Al2O3 crystallite size of not greater than 75 nm and a relative density of not less than 99% can be produced by preparing a Y2O3 partially stabilized ZrO2—Al2O3-based powder having a molar ratio (mol %) of zirconia (ZrO2) and yttria (Y2O3) of from 96.5:3.5 to 97.5:2.5 and a mass ratio (mass %) of ZrO2 containing Y2O3 and alumina (Al2O3) of from 85:15 to 75:25, molding this powder by cold isostatic pressing, and then performing sintering to a high density by microwave sintering for 45 to 90 min in an inert gas atmosphere at 1200 to 1400° C. When performing microwave sintering, a heating rate is preferably from 5 to 20° C./min up to 600° C. and from 50 to 150° C./min at 600° C. or higher.

Abstract: An exhaust gas purifying catalyst of the present invention includes: a first metal oxide selected from the group of praseodymium oxide, terbium oxide, and a combination thereof; a second metal oxide that is neodymium oxide; a third metal oxide that is zirconia or a combination of zirconia and ceria; and a fourth metal oxide selected from the group of lanthanum oxide, yttrium oxide, barium oxide, calcium oxide, strontium oxide, silicon oxide and a combination thereof.

Abstract: A ZrO2—Al2O3-based ceramic sintered compact containing tetragonal ZrO2 particles having a crystallite size of from 5 to 20 nm as a main component and having an ?-Al2O3 crystallite size of not greater than 75 nm and a relative density of not less than 99% can be produced by preparing a Y2O3 partially stabilized ZrO2—Al2O3-based powder having a molar ratio (mol %) of zirconia (ZrO2) and yttria (Y2O3) of from 96.5:3.5 to 97.5:2.5 and a mass ratio (mass %) of ZrO2 containing Y2O3 and alumina (Al2O3) of from 85:15 to 75:25, molding this powder by cold isostatic pressing, and then performing sintering to a high density by microwave sintering for 45 to 90 min in an inert gas atmosphere at 1200 to 1400° C. When performing microwave sintering, a heating rate is preferably from 5 to 20° C./min up to 600° C. and from 50 to 150° C./min at 600° C. or higher.

Abstract: The object of the present invention is to provide an oxide-based phosphor comprising elements other than rare earth elements as light-emitting elements, with low material costs, while achieving high luminous efficacy. The means for achieving the object is a phosphor comprising the following (1) to (3): (1) zirconium oxide, (2) titanium, and (3) at least one element selected from the group consisting of phosphorus, selenium, boron, and silicon.