A dielectric ceramic composition includes a barium titanate, an oxide of an R element, an oxide of an M element, and an oxide containing Si. The R element is one or more elements selected from Eu, Gd, Tb, Dy, Y, Ho, and Yb. The M element is one or more elements selected from Mg, Ca, Mn, V, and Cr. A ratio of an amount of the oxide of the R element in terms of R.sub.2O.sub.3 to an amount of the oxide containing Si in terms of SiO.sub.2 is 0.8:1 to 2.2:1. A ratio of an amount of the oxide of the M element in terms of MO to the amount of the oxide containing Si in terms of SiO.sub.2 is 0.2:1 to 1.8:1.50% or more of the number of dielectric particles constituting the dielectric ceramic composition is core-shell dielectric particles having a core-shell structure.

A perovskite ceramic composition that contains Sn, Ba, and Ti, and where the Sn content is within a range of about 0.001 parts by molSnabout 0.999 parts by mole with respect to 100 parts by mole of the Ti. The perovskite ceramic composition can be used in a composition that further includes a rare earth element R, Mn, and Si, and optionally Mg, where proportions of the R, the Mn, the Si, and the optional Mg, satisfy R: 0<Rabout 10 parts by mole, Mn: 0<Mnabout 5 parts by mole, Si: 0<Siabout 5 parts by mole Mg: 0<Mgabout 5 parts by mole with respect to 100 parts by mole of Ti.

An ink of the formula: 60-80% by weight BaTiO.sub.3 particles coated with SiO.sub.2; 5-50% by weight high dielectric constant glass; 0.1-5% by weight surfactant; 5-25% by weight solvent; and 5-25% weight organic vehicle. Also a dielectric made by: heating particles of BaTiO.sub.3 for a special heating cycle, under a mixture of 70-96% by volume N.sub.2 and 4-30% by volume H.sub.2 gas; depositing a film of SiO.sub.2 over the particles; mechanically separating the particles; forming them into a layer; and heating at 850-900 C. for less than 5 minutes and allowing the layer to cool to ambient temperature in N.sub.2 atmosphere.

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 method of making a glass sheet includes exposing a refractory block material comprising at least one multivalent component to a reducing atmosphere for a time and at a temperature sufficient to substantially reduce the at least one multivalent component of the refractory block material. The method also includes flowing molten glass over the refractory block material that has been exposed to the reducing atmosphere while preventing substantial re-oxidation of the at least one multivalent component.

A lead-free piezoelectric element that stably operates in a wide operating temperature range contains a lead-free piezoelectric material. The piezoelectric element includes a first electrode, a second electrode, and a piezoelectric material that includes a perovskite-type metal oxide represented by (Ba.sub.1-xCa.sub.x).sub.a(Ti.sub.1-yZr.sub.y)O.sub.3 (1.00a1.01, 0.02x0.30, 0.020y0.095, and yx) as a main component and manganese incorporated in the perovskite-type metal oxide. The manganese content relative to 100 parts by weight of the perovskite-type metal oxide is 0.02 parts by weight or more and 0.40 parts by weight or less on a metal basis.

The present disclosure provides methods to improve the properties of a porous structure formed by a rapid manufacturing technique. Embodiments of the present disclosure increase the bonding between the micro-particles 5 on the surface of the porous structure and the porous structure itself without substantially reduce the surface area of the micro-particles. In one aspect, embodiments of the present disclosure improves the bonding while preserving or increasing the friction of the structure against adjacent materials.

Provided are a method for producing a ceramic sintered body having improved light emission intensity, a ceramic sintered body, and a light emitting device. The method for producing a ceramic sintered body comprises preparing a molded body that contains a nitride fluorescent material having a composition containing: at least one alkaline earth metal element M.sup.1 selected from the group consisting of Ba, Sr, Ca, and Mg; at least one metal element M.sup.2 selected from the group consisting of Eu, Ce, Tb, and Mn; Si; and N, wherein a total molar ratio of the alkaline earth metal element M.sup.1 and the metal element M.sup.2 in 1 mol of the composition is 2, a molar ratio of the metal element M.sup.2 is a product of 2 and a parameter y and wherein y is in a range of 0.001 or more and less than 0.5, a molar ratio of Si is 5, and a molar ratio of N is 8, and wherein the nitride fluorescent material has a crystallite size, as calculated by X-ray diffraction measurement using the Halder-Wagner method, of 550 ? or less, and calcining the molded body at a temperature in a range of 1,600? C. or more and 2,200? C. or less to obtain a sintered body.

The present invention is directed to a porous pre-densified CeO.sub.2-stabilized ZrO.sub.2 ceramic having a density of 50.0 to 95.0%, relative to the theoretical density of zirconia, and an open porosity of 5 to 50% as well as to a densified CeO.sub.2-stabilized ZrO.sub.2 ceramic having a density of 97.0 to 100.0%, relative to the theoretical density of zirconia, and wherein the grains of the ceramic have an average grain size of 50 to 1000 nm, methods for the preparation of the pre-densified and densified ceramics and their use for the manufacture of dental restorations.

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. %.