A light-emitting ceramic that includes a pyrochlore type compound that contains 0.01 mol % or more of Bi with respect to 100 mol % of the general formula M1.sub.XM2.sub.YM3.sub.ZO.sub.W, wherein M1 is at least one of La, Y, Gd, Yb, and Lu, M2 is at least one of Zr, Sn, and Hf, M3 is at least one of Ta, Nb, and Sb, X, Y, Z, and W are positive numbers that maintain electrical neutrality, X+Y+Z=2.0, 0.005≤Z≤0.2, and 3X+4Y+5Z is 7.02 or less.

A gas nozzle having a fired surface excellent in particle reduction effect is provided. The gas nozzle 1 is a columnar gas nozzle made of sintered ceramics, provided with at least one through-hole 2 through which gas flows. The entire inner surface 2a of the through-hole 2 and the end face 1A on which outlet 2b of the through-hole 2 is provided are both fired surfaces. The inner surface 2a of the through-hole 2 has a first region A in the vicinity of the outlet 2b and a second region B which is located at a further position than the first region A. The average crystal grain size in the first region A is formed to be smaller than the average crystal grain size in the second region B.

A selection method includes: obtaining or providing multilayer ceramic capacitors each having a multilayer structure in which each of a plurality of ceramic dielectric layers and each of a plurality of internal electrode layers are alternately stacked; measuring a ratio of (a current value at 10 V/μm when a direct voltage is applied to a plurality of ceramic dielectric layers at 125 degrees C.)/(a current value at 10 V/μm when a direct voltage is applied to the plurality of the ceramic dielectric layers at 85 degrees C.), with respect to each multilayer ceramic capacitor; determining whether the ratio is in a predetermined range; and selecting a multilayer ceramic capacitor or multilayer ceramic capacitors each having a ratio in the predetermined range as a desired multilayer ceramic capacitor.

A dielectric composition includes a main ingredient having a perovskite structure represented by ABO.sub.3, where A is at least one of Ba, Sr, and Ca and B is at least one of Ti, Zr, and Hf, and a first accessory ingredient. The first accessory ingredient comprises 0.1 mole or more of a rare earth element, 0.02 mole or more of Nb, and 0.25 mole or more and 0.9 mole or less of Mg, a sum of contents of the rare earth element and Nb is 1.5 mole or less.

The present invention relates to a ceramic, to a process for preparing the ceramic and to the use of the ceramic as a dielectric in a capacitor.

Provided is a dielectric ceramic composition including a first component and a second component, wherein the first component comprises an oxide of Ca of 0.00 mol % to 35.85 mol % an oxide of Sr of 0.00 mol % to 47.12 mol %, an oxide of Ba of 0.00 mol % to 51.22 mol %, an oxide of Ti of 0.00 mol % to 17.36 mol %, an oxide of Zr of 0.00 mol % to 17.36 mol %, an oxide of Sn of 0.00 mol % to 2.60 mol %, an oxide of Nb of 0.00 mol % to 35.32 mol %, an oxide of Ta of 0.00 mol % to 35.32 mol %, and an oxide of V of 0.00 mol % to 2.65 mol %, and the second component includes at least (a) an oxide of Mn of 0.005% by mass to 3.500% by mass and (b) an oxide of Cu and/or an oxide of Ru.

A ceramic powder material containing a garnet-type compound containing Li, wherein the ceramic powder material has a pore volume of 0.4 mL/g or more and 1.0 mL/g or less.

The present invention relates to a conductive porous ceramic substrate and a method of manufacturing the same, and more particularly to a conductive porous ceramic substrate, in which a porous ceramic substrate used as a chuck or stage for fixing a thin semiconductor wafer substrate or display substrate through vacuum adsorption is imparted with antistatic performance so as to prevent the generation of static electricity, and a method of manufacturing the same.

An automated preparation method of a SiC.sub.f/SiC composite flame tube, comprising the following steps: preparing an interface layer for a SiC fiber by a chemical vapor infiltration process, and obtaining the SiC fiber with a continuous interface layer; laying a unidirectional tape on the SiC fiber with the continuous interface layer and winding the SiC fiber with the continuous interface layer to form and obtaining a preform of a net size molding according to a fiber volume and a fiber orientation obtained in a simulation calculation; and adopting a reactive melt infiltration process and the chemical vapor infiltration process successively for a densification and obtaining a high-density SiC.sub.f/SiC composite flame tube in a full intelligent way. The SiC.sub.f/SiC composite flame tube prepared by the present disclosure not only has a high temperature resistance, but also has a low thermal expansion coefficient, high thermal conductivity and high thermal shock resistance.

The sintered body has an average particle size in the range of 0.1 μm or more and 5 μm or less, includes gamet-type oxide base material particles having at least Li, La, and Zr, has 8% by volume or more of voids, and has an ionic conductivity of 1.0×10.sup.−5 S/cm or more at temperature of 25° C.