A mixed powder for a low temperature cofired ceramic material that contains 65 to 80 parts by weight of SiO.sub.2, 5 to 25 parts by weight of BaO, 1 to 10 parts by weight of Al.sub.2O.sub.3, 0.1 to 5 parts by weight of MnO, 0.1 to 5 parts by weight of B.sub.2O.sub.3, and 0.1 to less than 3 parts by weight of Li.sub.2O. The ceramic sintered body is used for, for example, ceramic electronic components, e.g., a multilayer circuit board or a coupler.

A method for producing an optical wavelength conversion member (9) composed of a sintered body containing, as main components, Al.sub.2O.sub.3 and a component represented by formula A.sub.3B.sub.5O.sub.12:Ce; an optical wavelength conversion member; an optical wavelength conversion component including the optical wavelength conversion member; and a light-emitting device including the optical wavelength conversion member or the optical wavelength conversion component. The production method of the sintered body includes firing in a firing atmosphere having a pressure of 10.sup.4 Pa or more and an oxygen concentration of 0.8 vol. % or more and less than 25 vol. %.

A ceramic capacitor includes a multilayer structure, wherein a main component of dielectric layers is ceramic expressed by a general formula A.sub.mBO.sub.3 (0.995m1.010), wherein the dielectric layers include a rare earth element Re as a first sub-component by 2.0 mol to 5.0 mol when converted into Re.sub.2O.sub.3/2, include Mg as a second sub-component by 1.0 mol to 3.0 mol when converted into MgO, include V as a third sub-component by 0.05 mol to 0.25 mol when converted into V.sub.2O.sub.5/2, include Si as a fourth sub-component by 0.5 mol to 5.0 mol when converted into SiO.sub.2, include an alkali earth metal element M as a fifth sub-component by 0.1 mol to 5.0 mol when converted into MCO.sub.3, on a presumption that an amount of the ceramic is 100 mol, wherein a ratio Si/V is 30 or less.

A multilayer ceramic capacitor (10) has a laminate body (20) constituted by dielectric layers (17) and internal electrode layers (18) stacked alternately. The dielectric layers (17) contain (Ba.sub.(1-x-y)Ca.sub.xSr.sub.y).sub.m(Ti.sub.(1-z)Zr.sub.z)O.sub.3, where 0.03x0.16, 0y0.02, 0<z0.02, 0.99m1.02, as a primary component, and an R oxide (R is a rare earth element) by 1.0 to 4.0 mol in equivalent element, an Mg compound by 0.2 to 2.5 mol in equivalent element, an Mn compound by 0.1 to 1.0 mol in equivalent element, a Zr compound by 0.1 to 2.0 mol in equivalent element, a V compound by 0.05 to 0.3 mol in equivalent element, and an Si compound by 0.2 to 5.0 mol in equivalent element, per 100 mol of the primary component. The multilayer ceramic capacitor can offer excellent DC bias properties and ensure high reliability.

A method of altering a surface of a ceramic matrix composite to aid in nodule removal is described. A fiber preform comprising a framework of ceramic fibers is heated to a temperature at or above a melting temperature of silicon. During the heating, the fiber preform is infiltrated with a molten material comprising silicon. After the infiltration, the fiber preform is cooled, and the infiltrated fiber preform is exposed to a gas comprising nitrogen during cooling. Silicon nitride may be formed by a reaction of free (unreacted) silicon at or near the surface of the infiltrated fiber preform with the nitrogen. Thus, a ceramic matrix composite having a surface configured for easy nodule removal is formed. Any silicon nodules formed on the surface during cooling may be removed without machining or heat treatment.

A ceramic electronic device includes: a multilayer structure; and a cover layer, wherein a concentration of Mn of the cover layer with respect to a main component ceramic is larger than a concentration of Mn of the dielectric layers with respect to a main component ceramic in a capacity section, wherein an average crystal grain diameter of a first dielectric layer is smaller than that of a second dielectric layer, and a concentration of Mn of the first dielectric layer with respect to the main component ceramic is larger than a concentration of Mn of the second dielectric layer with respect to the main component ceramic, in the capacity section.

The present invention discloses novel methods for producing highly porous ceramic and/or metal aerogel monolithic objects that are hard, sturdy, and resistant to high temperatures. These methods comprise preparing nanoparticulate oxides of metals and/or metalloids via a step of vigorous stirring to prevent gelation, preparing polymer-modified xerogel powder compositions by reacting said nanoparticulate oxides with one or more polyfunctional monomers, compressing said polymer-modified xerogel powder compositions into shaped compacts, and carbothermal conversion of the shaped xerogel compacts via pyrolysis to provide the highly porous ceramic and/or metal aerogel monolithic objects that have the same shapes as to their corresponding xerogel compact precursors. Representative of the highly porous ceramic and/or metal aerogel monolithic objects of the invention are ceramic and/or metal aerogels of Si, Zr, Hf, Ti, Cr, Fe, Co, Ni, Cu, Ru, Au, and the like. Examples include sturdy, shaped, highly porous silicon carbide (SiC), silicon nitride (Si.sub.3N.sub.4), zirconium carbide (ZrC), hafnium carbide (HfC), chromium carbide (Cr.sub.3C.sub.2), titanium carbide (TiC), zirconium boride (ZrB.sub.2), hafnium boride (HfB.sub.2), and metallic aerogels of iron (Fe), nickel (Ni), cobalt (Co), copper (Cu), ruthenium (Ru), gold (Au), and the like. Said aerogel monolithic objects have utility in various applications such as, illustratively, in abrasives, in cutting tools, as catalyst support materials such as in reformers and converters, as filters such as for molten metals and hot gasses, in bio-medical tissue engineering such as bone replacement materials, in applications requiring strong lightweight materials such as in automotive and aircraft structural components, in ultra-high temperature ceramics, and the like.

A ceramic electronic device includes: a multilayer structure in which each of dielectric layers and each of internal electrode layers are alternately stacked, a main component of the dielectric layers being ceramic, wherein a relationship of I.sub.A/I.sub.B>1.40 is satisfied in a TSDC (Thermally Stimulated Depolarization Currents) of temperature elevation rate of 10 degrees C./min under a condition of 130 degrees C., 5 V/m and a polarization of 30 min, when a peak current value on a lower temperature side in a temperature range of 130 degrees C. to 190 degrees C. is I.sub.A and a peak current value on a higher temperature side in a temperature range of 190 degrees C. to 280 degrees C. is I.sub.B.

Cordierite-forming batch mixtures including one or more non-oxide inorganic source materials or materials as pore-formers are provided. Non-oxide inorganic materials, such a non-oxide silicon material that includes at least one of silicon carbide, silicon, or silicon nitride, may be added to cordierite-forming batch mixtures as at least a partial replacement for conventional inorganic pore-formers. Non-oxide inorganic pore-formers may provide an increase in pore volume while having a reduced coefficient of thermal expansion impact as compared with conventional pore-formers. Cordierite-forming mixtures as disclosed herein may additionally include rare-earth catalysts and alkaline-earth materials that may enhance the pore-forming effect of non-oxide inorganic pore-formers without significant exothermic reactions or the production of emissions that may require additional processing treatments.

An oxide superconductor of an embodiment includes an oxide superconductor layer having a continuous Perovskite structure including rare earth elements, barium (Ba), and copper (Cu). The rare earth elements include a first element which is praseodymium, at least one second element selected from the group consisting of neodymium, samarium, europium, and gadolinium, at least one third element selected from the group consisting of yttrium, terbium, dysprosium, and holmium, and at least one fourth element selected from the group consisting of erbium, thulium, ytterbium, and lutetium. When the number of atoms of the first element is N(PA), the number of atoms of the second element is N(SA), and the number of atoms of the fourth element is N(CA), 1.5(N(PA)+N(SA))N(CA) or 2(N(CA)N(PA))N(SA) is satisfied.