Abstract: An alumina having a multimodal particle size distribution wherein at least one of the particle sizes giving local maximum values in the particle size distribution is less than 10 ?m, and wherein the alumina comprises 1 to 5 wt % of at least one of La and Ba.

Abstract: An alumina having a multimodal particle size distribution wherein at least one of the particle sizes giving local maximum values in the particle size distribution is less than 10 ?m, and wherein the alumina comprises 1 to 5 wt % of at least one of La and Ba.

Abstract: A method for producing a silicate-based oxynitride phosphor, comprising a step of firing a raw material mixture while contacting the raw material mixture with a Si-containing gas containing gas phase Si to generate a silicate-based oxynitride phosphor.

Abstract: A crystalline material represented by M12a(M2bLc)M3dOyNx wherein M1 is at least one element selected from alkali metals, M2 is at least one element selected from Ca, Sr, and Ba, M3 is at least one element selected from Si and Ge, L is at least one element selected from rare earth elements, Bi, and Mn, a is 0.9 to 1.5, b is 0.8 to 1.2, c is 0.005 to 0.2, d is 0.8 to 1.2, x is 0.001 to 1.0, and y is 3.0 to 4.0 or less.

Abstract: A method for producing a crystalline material comprising a step of firing a raw material mixture containing M1, M2, M3, and L in an atmosphere containing NH3 gas to generate a crystalline material represented by M12a(M2bLc)M3dOyNx

Abstract: Provided are phosphors that can exhibit higher emission luminance. Phosphors in which the activator is included in a compound represented by Formula xM1O.M2O.yM3O2 (wherein M1 represents one or more of a group comprising Ca, Sr and Ba, M2 represents Mg and/or Zn, M3 represents Si and/or Ge, x is a value in the range 4 to 6 and y is a value in the range 2 to 4). Phosphors represented by Formula M15(1?z)EuzM2M33O12 (wherein M1, M2 and M3 have the same meanings as above, and z is a value in the range 0.0001 to 0.3). The above phosphors have the same crystal structure as bredigite.

Abstract: A barium titanate powder and a method for producing the same are provided. The barium titanate powder comprises a perovskite structure having a ratio c/a of 1.008 or more and ratio d/D of from 1 to 1.5, wherein “c” is a length of the c axis, “a” is a length of the a axis in the perovskite structure, “d” is an average particle diameter and “D” is a equivalent specific surface area diameter. The method of producing a barium titanate powder, comprises the steps of: (1) heating a mixture containing a titanium compound and a barium compound under a gas atmosphere containing a halogen at a temperature of not less than about 200° C. and less than the temperature for generation of barium titanate, (2) calcining the obtained mixture under an atmosphere containing substantially no halogen at a temperature of not lower than the temperature for generation of barium titanate.

Abstract: Provided is a fluorescent body for use in a near-ultraviolet excitation light-emitting element, comprising the compound given by formula (1), having part of element M1 and/or M2 therein replaced by an activation element (M3). M1aM2bPcO15(1) (Here, M1 represents one or more elements chosen from the group comprising Ca, Sr, and Ba; M2 represents one or more elements chosen from the group comprising Mg and Zn; a is a number between 1.5 and 2.5, inclusive; b is a number between 2.5 and 3.5, inclusive; and c is a number between 3.5 and 4.5, inclusive.) A fluorescent body in which M1 is Sr and M2 is Mg, and a fluorescent body in which M3 is Eu are preferable. Also provided are a fluorescent paste having the fluorescent body, and a near-ultraviolet excitation light-emitting element having the fluorescent body and having a high luminescent intensity.

Abstract: Provided are phosphors that can exhibit higher emission luminance. Phosphors in which the activator is included in a compound represented by Formula xM1O.M2O.yM3O2 (wherein M1 represents one or more of a group comprising Ca, Sr and Ba, M2 represents Mg and/or Zn, M3 represents Si and/or Ge, x is a value in the range 4 to 6 and y is a value in the range 2 to 4). Phosphors represented by Formula M15(1?z)EuzM2M33O12 (wherein M1, M2 and M3 have the same meanings as above, and z is a value in the range 0.0001 to 0.3). The above phosphors have the same crystal structure as bredigite.

Abstract: Provided are phosphors that can provide emission devices that can further improve emission characteristics, principally, color rendering. Disclosed are phosphors made by substituting at least a portion of M2 in compounds represented by Formula (1) with M4 (M4 represents a trivalent cationic element), substituting a portion of O in said compound with M5 (M5 represents a trivalent anionic element) and substituting a portion of M1 and/or M2 in said compound with an activated element. In Formula (1): aM1O.3M2O.6M3O2 (In Formula (1), M1 represents one or more alkaline-earth elements selected from a group comprising Ba, Sr and Ca, M2 represents one or more divalent metal elements selected from a group comprising Mg and Zn, M3 represents a tetravalent metal element and a is a value in the range 3 to 9.

Abstract: Provided is a fluorescent body for use in a near-ultraviolet excitation light-emitting element, comprising the compound given by formula (1), having part of element M1 and/or M2 therein replaced by an activation element (M3). M1aM2bPcO15(1) (Here, M1 represents one or more elements chosen from the group comprising Ca, Sr, and Ba; M2 represents one or more elements chosen from the group comprising Mg and Zn; a is a number between 1.5 and 2.5, inclusive; b is a number between 2.5 and 3.5, inclusive; and c is a number between 3.5 and 4.5, inclusive.) A fluorescent body in which M1 is Sr and M2 is Mg, and a fluorescent body in which M3 is Eu are preferable. Also provided are a fluorescent paste having the fluorescent body, and a near-ultraviolet excitation light-emitting element having the fluorescent body and having a high luminescent intensity.

Abstract: A barium titanate powder and a method for producing the same are provided. The barium titanate powder comprises a perovskite structure having a ratio c/a of 1.008 or more and ratio d/D of from 1 to 1.5, wherein “c” is a length of the c axis, “a” is a length of the a axis in the perovskite structure, “d” is an average particle diameter and “D” is a equivalent specific surface area diameter. The method of producing a barium titanate powder, comprises the steps of: (1) heating a mixture containing a titanium compound and a barium compound under a gas atmosphere containing a halogen at a temperature of not less than about 200° C. and less than the temperature for generation of barium titanate, (2) calcining the obtained mixture under an atmosphere containing substantially no halogen at a temperature of not lower than the temperature for generation of barium titanate.

Abstract: A metal oxide powder except &agr;-alumina, comprising polyhedral particles having at least 6 planes each, a number average particle size of from 0.1 to 300 &mgr;m, and a D90/D10 ratio of 10 or less where D10 and D90 are particle sizes at 10% and 90% accumulation, respectively from the smallest particle size side in a cumulative particle size curve of the particles. This metal oxide powder contains less agglomerated particles, and has a narrow particle size distribution and a uniform particle shape.

Abstract: A metal oxide powder except &agr;-alumina, is disclosed comprising polyhedral particles having at least 6 planes each, a number average particle size of from 0.1 to 300 &mgr;m, and a D90/D10 ratio of 10 or less where D10 and D90 are particle sizes at 10% and 90% accumulation, respectively from the smallest particle size side in a cumulative particle size curve of the particles. This metal oxide powder contains less agglomerated particles, and has a narrow particle size distribution and a uniform particle shape.

Abstract: An inorganic porous sintered body comprising inorganic particles of polyhedral crystals, said inorganic porous sintered body having pores formed by the inorganic particles, wherein said pores have a pore size distribution that a ratio of D10 to D90 is not more than 3 and D50 is 0.01-5 .mu.m when D10, D50 and D90 are pore sizes at 10%, 50% and 90% cumulation from the largest pore size of a cumulative pore volume distribution, respectively, and a porosity is 10-50%.

Abstract: A complex metal oxide powder having at least two metal elements, which contains polyhedral particles each having at least 6 planes, a number average particle size of from 0.1 to 500 .mu.m, and a D.sub.90 /D.sub.10 ratio of 10 or less in which D.sub.10 and D.sub.90 are particle sizes at 10% and 90% accumulation, respectively from the smallest particle size side in a cumulative particle size curve of the particles, and an yttrium-aluminum garnet powder containing polyhedral particles each having at least 6 planes, and a number average particle size of 20 to 500 .mu.m. These complex metal oxides contain less agglomerated particles, and have a narrow particle size distribution and a uniform particle shape.

Abstract: A method of preparing dense sintered bodies of beta alumina suitable for solid electrolytes, which comprises preparing a shaped body from a mixture containing an aluminum powder, a sodium compound, a structure stabilizer and a zirconia powder or from a mixture containing an aluminum powder, an alumina powder, a sodium compound, a structure stabilizer and a zirconia powder, and reaction-sintering the shaped body.