Sintered product having a relative density of greater than 90%, with, to more than 80% of the volume thereof, a stack of flat ceramic platelets, the assembly of the platelets having a mean thickness of less than 3 μm, having a width of greater than 50 mm, and including more than 20% of alumina, as a percentage on the basis of the weight of the product. The width of the product is the largest dimension measured in the plane in which the length of the product is measured, along a direction perpendicular to the direction of the length. The length of the product is the largest dimension thereof in a plane parallel to the general plane in which the platelets extend.

Provided is a dielectric ceramic composition comprising a main component of forsterite and calcium strontium titanate. A content ratio of forsterite in the main component is from 84.0 to 92.5 parts by mole, and a content ratio of calcium strontium titanate is from 7.5 to 16.0 parts by mole. (Sr+Ca)/Ti in the calcium strontium titanate is from 1.03 to 1.20 in terms of a molar ratio. With respect to a total of 100 parts by mass of the main component and a subcomponent except for Li-containing glass, from 2 to 10 parts by mass of Li-containing glass is added. The Li-containing glass includes Al.sub.2O.sub.3 in an amount of from 1% by mass to 10% by mass.

A capacitor body includes a plurality of dielectric layers and a plurality of internal electrode layers stacked alternately. The plurality of dielectric layers include crystal grains of barium titanate, a rare earth element, and silicon. The crystal grains include a first crystal grain and a second crystal grain. The crystal grains each include a surface layer as a shell and an interior portion surrounded by the shell as a core. The first crystal grain has a higher concentration distribution of the rare earth element in the shell than in the core. The second crystal grain has distribution in which a ratio of a concentration of the silicon in the core and the shell is lower than a ratio of a concentration of the rare earth element in the core and the shell in the first crystal grain.

A ceramic product and a method of producing the ceramic product produced by pretreating the feedstock from at least of iron/steel recovery, recovery of at least one non-ferrous material, sieving, crushing, milling, aging, and thermal treatment, receiving as a first powder a first recovered material from the pretreating, receiving as a second powder a second recovered material from the pretreating, combining the first and second powders with water to form at least one of an extrudable paste and a granulated mixture, forming a green body from the at least one of the extrudable paste after extrusion and the granulated mixture; drying the green body, firing the green body to form the ceramic product, and cooling the ceramic product.

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.

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 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 monolithic separation membrane structure includes a monolithic base, an intermediate layer and a separation membrane. The monolithic base has a plurality of filtration cells extending from a first end face to a second end face. The intermediate layer is formed on an inner surface of the filtration cells. The separation membrane is formed on an inner surface of the intermediate layer. An inner diameter not including the intermediate layer and the separation membrane of the plurality of respective filtration cells is greater than or equal to 1.0 mm to less than or equal to 2.0 mm. A partition wall thickness not including the intermediate layer and the separation membrane of the shortest portion of two adjacent filtration cells of the plurality of filtration cells is greater than or equal to 0.05 mm to less than 0.2 mm. A thickness of the intermediate layer is greater than or equal to 20 μm to less than 100 μm.

A dielectric ceramic composition includes a barium titanate (BaTiO.sub.3)-based base material main ingredient and an accessory ingredient, the accessory ingredient including dysprosium (Dy) and praseodymium (Pr) as first accessory ingredients. A content of the Pr satisfies 0.233 mol≤Pr≤0.699 mol, based on 100 mol of the barium titanate base material main ingredient.

A dielectric ceramic composition includes a barium titanate (BaTiO.sub.3)-based base material main ingredient and an accessory ingredient, the accessory ingredient including dysprosium (Dy) and praseodymium (Pr) as first accessory ingredients. A content of the Pr satisfies 0.233 mol≤Pr≤0.699 mol, based on 100 mol of the barium titanate base material main ingredient.