A pore-free ceramic is provided that has a high modulus of elasticity and a low coefficient of thermal expansion. A process for producing a corresponding ceramic is also provided. The pore free ceramic is a dimensionally stable substrate material in applications subjected to temperature gradients including semiconductor manufacture.

A ceramic substrate made of a dielectric material including silicon carbide particles, which is used as a forming material, in which the number of the silicon carbide particles per unit area on the surface of the substrate is smaller than the number of the silicon carbide particles per unit area in a cross section of the substrate.

Disclosed is a method for manufacturing a ceramic susceptor, the method including: preparing ceramic sheets; preparing a lamination structure of a molded body, in which the ceramic sheets are laminated and a conductive metal layer for electrodes is disposed between the ceramic sheet laminated products; and sintering the lamination structure of the molded body, wherein the preparing of the ceramic sheets includes: obtaining a vitrified first additive powder by heat-treating a slurry containing MgO, SiO.sub.2, and CaO; preparing a slurry by mixing an Al.sub.2O.sub.3 powder with the first additive powder, a second additive powder containing a MgO powder, and a third additive powder containing a Y.sub.2O.sub.3 powder; and forming the ceramic sheets by tape casting the slurry.

A dielectric composition and a multilayer capacitor including the same are disclosed. The dielectric composition including: a BaTiO.sub.3-based main ingredient; a first auxiliary ingredient including rare earth elements; and a second auxiliary ingredient including at least one of Ba and Ca but essentially including Ba, wherein the rare earth elements include Tb and Dy, and the first auxiliary ingredient and the second auxiliary ingredient satisfy a molar content condition of 0.40<(Tb/T_RE)*(Ba+Ca)<0.93, where T_RE is a total molar content of the rare earth elements in the first auxiliary ingredient.

A heat dissipation member includes a thermal radiation ceramic material, and the thermal radiation ceramic material contains silicon nitride and boron nitride as main components. The ratio of the mass of boron nitride to the mass of silicon nitride and boron nitride is 10 mass % to 40 mass %.

A dielectric body includes a plurality of crystal grains of which a main component is barium titanate, and an additive including Zr, Eu and Mn. At least one of the plurality of crystal grains has a core-shell structure having a core and a shell. A Zr/Ti atomic concentration ratio is 0.02 or more and 0.10 or less. An Eu/Ti atomic concentration ratio is 0.001 or more and 0.03 or less. A Mn/Ti atomic concentration ratio is 0.005 or more and 0.05 or less. A total atomic concentration of the one or more rare elements is smaller than an atomic concentration of Eu when the dielectric body has the one or more rare earth elements. A median diameter of the plurality of crystal grains is 200 nm or more and 400 nm or less.

A composition comprises a zirconia powder, in which 55% or more thereof is monoclinic, and a stabilizer capable of suppressing phase transition of zirconia. An average particle diameter of zirconia particles and particles of the stabilizer is 0.06 μm to 0.17 μm. At least a portion of the stabilizer does not form a solid solution with zirconia.

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.

A sintered body includes a solid solution containing cobalt and iron, with the balance being zirconia. The total content of cobalt in terms of CoO and iron in terms of Fe.sub.2O.sub.3 is more than 0.1 wt % and less than 3.0 wt %, and the proportion of cobalt regions larger than 5.5 μm.sup.2 in an elemental map obtained using an electron probe microanalyzer is 25% or less.

A grain-grade zirconia toughened alumina ceramic substrate and a method for preparing the same. The ceramic substrate is prepared from alumina power (main phase) and zirconia powder (secondary phase) in a binary azeotrope of anhydrous ethanol and butanone in the presence of magnesia-alumina spinel powder (as sintering aid), phosphate ester (as dispersant), polyvinyl butyral (as binder) and dibutyl phthalate (as plasticizer). In a mixture of the alumina power and the zirconia powder, a volume percentage of the alumina power is 82.44-96.7%, and a volume percentage of the zirconia powder is 3.30-17.56%. The magnesia-alumina spinel powder is 0.1-4.0% by weight of the mixture of the alumina power and the zirconia powder. A particle size ratio of the alumina powder to the zirconia powder is 2.415-4.444.