An air-permeable member of the present disclosure includes a porous ceramic having a columnar or plate shape. A root mean square slope RΔq in a roughness curve of an outer peripheral surface of the porous ceramic is greater than a root mean square slope RΔq in a roughness curve of a main surface of the porous ceramic.

This document describes processes for preparing ceramics, especially lithium-based ceramics. The ceramics produced by this process and their use in electrochemical applications are also described as well as electrode materials, electrodes, electrolyte compositions, and electrochemical cells comprising them.

This document describes processes for preparing ceramics, especially lithium-based ceramics. The ceramics produced by this process and their use in electrochemical applications are also described as well as electrode materials, electrodes, electrolyte compositions, and electrochemical cells comprising them.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

A dielectric ceramic composition comprising a main component comprising an oxide represented by:
U.sub.aX.sub.bY.sub.cZ.sub.d((Ca.sub.1-x-ySr.sub.xM.sub.y).sub.m(Zr.sub.1-u-vTi.sub.uHf.sub.v)O.sub.3).sub.1-a-b-c-d
wherein the elements defined by U, X, Y, Z and M and subscripts a, b, c, d, x, y, m, u and v are defined.

A dielectric ceramic composition comprising a main component comprising an oxide represented by:
U.sub.aX.sub.bY.sub.cZ.sub.d((Ca.sub.1-x-ySr.sub.xM.sub.y).sub.m(Zr.sub.1-u-vTi.sub.uHf.sub.v)O.sub.3).sub.1-a-b-c-d
wherein the elements defined by U, X, Y, Z and M and subscripts a, b, c, d, x, y, m, u and v are defined.

It is described a process for producing transparent ceramic bodies with at least two zones having different garnet composition, in particular in which one of said zones has composition Y.sub.3AI.sub.5O.sub.12. The invention is especially useful for the production of transparent ceramic bodies having preset complex shapes and/or a controlled complex distribution of doping ions.

The invention provides a sintered rare earth metal oxide target for producing a radioisotope in an instrumentation tube of a nuclear power reactor, wherein the sintered target has a density of at least 90 percent of the theoretical density, and wherein the sintered target contains chromium in an amount of from 500 to 2000 μg/g, and Mg and/or Ca in an amount of from 1000 to 6000 μg/g. The sintered target is prepared by providing a rare earth metal oxide powder, blending the rare earth metal oxide powder with chromium oxide, dry granulating and consolidating the powder in a mold to form a spheroidal green body, and sintering the green body in solid phase to form a spheroidal ytterbia target.

The invention provides a sintered rare earth metal oxide target for producing a radioisotope in an instrumentation tube of a nuclear power reactor, wherein the sintered target has a density of at least 90 percent of the theoretical density, and wherein the sintered target contains chromium in an amount of from 500 to 2000 μg/g, and Mg and/or Ca in an amount of from 1000 to 6000 μg/g. The sintered target is prepared by providing a rare earth metal oxide powder, blending the rare earth metal oxide powder with chromium oxide, dry granulating and consolidating the powder in a mold to form a spheroidal green body, and sintering the green body in solid phase to form a spheroidal ytterbia target.

A metal-ceramic composite for a fuel cell anode is disclosed. In the metal-ceramic composite, the content of the metal is greatly reduced and the intervals between the metal particles are maintained constant, achieving improved activity and conductivity. The metal-ceramic composite includes a metal catalyst raw material and a mixed-conductive ceramic. The metal catalyst raw material is present in an amount such that the content of the metal catalyst nanoparticles in the metal-ceramic composite is significantly lower than in conventional metal-ceramic composites. The presence of a small amount of the metal catalyst nanoparticles in the metal-ceramic composite minimizes the occurrence of stress resulting from a change in the volume of the metal catalyst and provides a solution to the problem of defects, achieving improved life characteristics. Also disclosed is a method for preparing the metal-ceramic composite.