Abstract: A sintered material is provided having a phase of a compound at least containing a rare earth element and fluorine, the sintered material having an L* value of 70 or more in the L*a*b* color space. The crystal grains of the sintered material preferably has an average grain size of 10 ?m or less. The sintered material preferably has a relative density of 95% or more. The sintered material preferably has a three-point flexural strength of 100 MPa or more. The sintered material preferably contains no oxygen, or preferably has an oxygen content of 13% by mass or less when containing oxygen. The compound is preferably rare earth element fluoride or oxyfluoride.

Abstract: The present invention provides an abrasive material capable of polishing difficult-to-polish silicon carbide at a high degree of surface precision. The present invention relates to an abrasive material including manganese dioxide particles having a non-needle-like shape possessing a ratio of the longitudinal axis to the transverse axis of the particles observed with a scanning electron microscope of 3.0 or less. The abrasive material is preferable if the average particle size DSEM of the longitudinal axis of the observed particles is 1.0 ?m or less, and if the particle size D50 of the volume-based cumulative fraction of 50% in laser diffraction/scattering particle size distribution measurement is 2.0 ?m or less.

Abstract: Provided is an exhaust-gas-purification catalyst carrier that contains a ceria-zirconia complex oxide having a pyrochlore phase and a novel exhaust-gas-purification catalyst carrier that exhibit excellent OSC performance at any temperature region of a low temperature (around 400° C.) and a high temperature (around 800° C.). Proposed is the exhaust-gas-purification catalyst carrier containing a ceria-zirconia complex oxide which has a pyrochlore phase and is 7.0 m2/g or more in specific surface area and in the range of 100 ? to 700 ? in crystallite size.

Abstract: The present invention provides an abrasive material capable of polishing difficult-to-polish silicon carbide at a high degree of surface precision. The present invention relates to an abrasive material including manganese dioxide particles having a non-needle-like shape possessing a ratio of the longitudinal axis to the transverse axis of the particles observed with a scanning electron microscope of 3.0 or less. The abrasive material is preferable if the average particle size DSEM of the longitudinal axis of the observed particles is 1.0 ?m or less, and if the particle size D50 of the volume-based cumulative fraction of 50% in laser diffraction/scattering particle size distribution measurement is 2.0 ?m or less.

Abstract: Provided is an exhaust-gas-purification catalyst carrier that contains a ceria-zirconia complex oxide having a pyrochlore phase and a novel exhaust-gas-purification catalyst carrier that exhibit excellent OSC performance at any temperature region of a low temperature (around 400° C.) and a high temperature (around 800° C.). Proposed is the exhaust-gas-purification catalyst carrier containing a ceria-zirconia complex oxide which has a pyrochlore phase and is 7.0 m2/g or more in specific surface area and in the range of 100 ? to 700 ? in crystallite size.

Abstract: The present invention provides a polishing technique which enables polishing of silicon carbide, which is difficult to be polished, with high efficiency and high surface accuracy. The present invention relates to a polishing slurry for polishing a substrate, which comprises abrasive particles containing manganese oxide as a main component and in which the content of the abrasive particles is less than 10% by weight based on the polishing slurry. The polishing slurry of the present invention has a pH of preferably 7 or more. It is particularly preferable to use manganese dioxide as abrasive particles. The polishing slurry of the present invention is suitable for a substrate of silicon carbide.

Abstract: The present invention provides an abrasive treatment technique capable of planarizing at an extremely high rate silicon carbide, which is thermally and chemically extremely stable and for which it is extremely difficult to efficiently perform an abrasive treatment. The present invention is a polishing slurry for silicon carbide wherein the polishing slurry includes a suspension liquid in which the pH thereof is 6.5 or more and manganese dioxide particles are suspended. The polishing slurry for silicon carbide is preferably a suspension in which manganese dioxide particles are suspended in an aqueous solution allowed to have a redox potential falling in a range enabling manganese to be present as manganese dioxide. The redox potential V of the polishing slurry preferably falls within the range specified by the following formula representing a relation between V and pH, pH being a variable: 1.014?0.591 pH?V?1.620?0.

Abstract: The present invention provides an abrasive material capable of polishing difficult-to-polish silicon carbide at a high degree of surface precision. The present invention relates to an abrasive material including manganese dioxide particles having a non-needle-like shape possessing a ratio of the longitudinal axis to the transverse axis of the particles observed with a scanning electron microscope of 3.0 or less. The abrasive material is preferable if the average particle size DSEM of the longitudinal axis of the observed particles is 1.0 ?m or less, and if the particle size D50 of the volume-based cumulative fraction of 50% in laser diffraction/scattering particle size distribution measurement is 2.0 ?m or less.

Abstract: Nickel powder includes, on the basis of the total number of particles, not less than 10% of particles whose particle size is not less than 1.2 times the average particle size, as determined by the SEM observation; and not less than 10% of particles whose particle size is not more than 0.8 times the average particle size, as determined by the SEM observation. The nickel powder can be prepared by, for instance, precipitating nickel particles from an aqueous solution containing a nickel salt and a hydrazine reducing agent, without forming any hydroxide of nickel as an intermediate. A conductive paste containing the nickel powder can be applied onto an internal or external electrode for electronic parts.

Abstract: Nickel powder includes, on the basis of the total number of particles, not less than 10% of particles whose particle size is not less than 1.2 times the average particle size, as determined by the SEM observation; and not less than 10% of particles whose particle size is not more than 0.8 times the average particle size, as determined by the SEM observation. The nickel powder can be prepared by, for instance, precipitating nickel particles from an aqueous solution containing a nickel salt and a hydrazine reducing agent, without forming any hydroxide of nickel as an intermediate. A conductive paste containing the nickel powder can be applied onto an internal or external electrode for electronic parts.

Abstract: Nickel powder comprises, on the basis of the total number of particles, not less than 10% of particles whose particle size is not less than 1.2 time the average particle size, as determined by the SEM observation; and not less than 10% of particles whose particle size is not more than 0.8 time the average particle size, as determined by the SEM observation. The nickel powder can be prepared by, for instance, precipitating nickel particles from an aqueous solution containing a nickel salt and a hydrazine reducing agent, without forming any hydroxide of nickel as an intermediate. A conductive paste containing the nickel powder can be applied onto the positions on which an internal or external electrode for electronic parts and then baking the coated paste to give an electrode.

Abstract: Nickel powder herein disclosed is characterized in that it has an average particle size as determined through the observation by a scanning electron microscope (SEM) ranges from 0.1 to 1 &mgr;m and that the D5 0 value as determined by laser diffraction-scattering particle size distribution analysis and the average particle size as determined by SEM observation satisfy the following relation represented by Formula (1): 1≦[(D5 0 value)/(average particle size as determined by SEM observation)]≦1.8  (1) The nickel powder is highly dispersible in an organic vehicle during the preparation of a conductive paste because it has low agglomerate properties and it is in an approximately monodispersed condition and the nickel powder is particularly suitable in the preparation of a conductive paste for use in making a thin internal electrode of a multilayer ceramic capacitor, which is free of any projection, because of it sharp particle distribution.

Abstract: The composite nickel fine powder includes surface-oxidized nickel fine particles and at least one member selected from the group consisting of oxides and complex oxides of at least one metal element having an atomic number ranging from 12 to 56 or 82 and belonging to Group 2 to 14 of the Periodic Table on the surface of the surface-oxidized nickel fine particles.

Abstract: The promoter includes (A) particulate aluminum oxide and (B) a double oxide of (i) cerium and (ii) at least one member selected from the group consisting of zirconium, yttrium, strontium, barium and rare earth elements, supported on the particulate aluminum oxide. A solution of (i) a water-soluble salt of cerium and (ii) a water-soluble salt of at least one member selected from the group consisting of zirconium, yttrium, strontium, barium and rare earth elements is formed. Particulate aluminum oxide is added to the solution to form a dispersion. An aqueous solution of ammonium hydrogen carbonate is added to the dispersion to obtain particulate aluminum oxide coated with a reaction product. The particulate aluminum oxide coated with the reaction product is fired. Alternatively, an aqueous solution containing (i) the water-soluble salt of cerium and (ii) the water-soluble salt of the at least one member dissolved therein is adhered onto particulate aluminum oxide.

Abstract: Nickel powder herein disclosed has an average particle size, as determined by the observation with SEM, of not more than 1 &mgr;m, a particle density of not less than 8.0 g/cm3, and an average diameter of crystallites present in the nickel particles of not more than 550 Å. Moreover, a conductive paste for a multilayer ceramic capacitor comprises the foregoing nickel powder. The nickel powder and the conductive paste containing the same can control heat shrinkage while inhibiting any rapid oxidation and permit the production of a thin, uniform internal electrode for a multilayer ceramic capacitor without being accompanied by any crack formation and delamination during firing.

Abstract: The composite nickel fine powder includes surface-oxidized nickel fine particles and at least one member selected from the group consisting of oxides and complex oxides of at least one metal element having an atomic number ranging from 12 to 56 or 82 and belonging to Group 2 to 14 of the Periodic Table on the surface of the surface-oxidized nickel fine particles.

Abstract: Composite nickel fine powder comprises metal nickel fine particles, at least one member attached to the surface of the fine particles and selected from the group consisting of oxides and double oxides containing at least one metal element selected from the group consisting of the Groups 2 to 14 of the Periodic Table and whose atomic number falls within the range of from 12 to 82, and a saturated or unsaturated fatty acid supported on the surface of the nickel fine particles provided thereon with the oxide and/or double oxide attached thereto. The composite nickel fine powder is excellent in resistance to heat shrinkage, has a high tap density, and has characteristic properties suitable for use as a material for making a conductive paste.

Abstract: Nickel powder herein disclosed is characterized in that it has an average particle size as determined through the observation by a scanning electron microscope (SEM) ranges from 0.

Abstract: Nickel powder herein disclosed has an average particle size, as determined by the observation with SEM, of not more than 1 &mgr;m, a particle density of not less than 8.0 g/cm3, and an average diameter of crystallites present in the nickel particles of not more than 550 Å. Moreover, a conductive paste for a multilayer ceramic capacitor comprises the foregoing nickel powder. The nickel powder and the conductive paste containing the same can control heat shrinkage while inhibiting any rapid oxidation and permit the production of a thin, uniform internal electrode for a multilayer ceramic capacitor without being accompanied by any crack formation and delamination during firing.

Abstract: Nickel fine powder comprises nickel and phosphorus dispersed in the nickel in an amount ranging from 0.01 to 2% by weight on the basis of the weight of the nickel and having a particle size of not more than 0.5 &mgr;m. The nickel fine powder can be prepared by a method comprising the step of reducing nickel hydroxide in the presence of phosphorus ions in such an amount that the molar ratio of phosphorus ions to nickel ions falls within the range of from 0.01 to 2.