A ceramic composite and a method of preparing the same are provided. The method of preparing the ceramic composite includes mixing an aluminum slag and a carbon accelerator to obtain a mixture and reacting the mixture at a temperature equal to or greater than 1600° C. in a nitrogen atmosphere to obtain a ceramic composite. The aluminum slag includes aluminum, oxygen, nitrogen, and magnesium. The weight ratio of the oxygen to the aluminum is 0.6 to 2. The weight ratio of the nitrogen to the aluminum is 0.1 to 1.2. The weight ratio of the magnesium to the aluminum is 0.04 to 0.2. The ceramic composite includes aluminum nitride accounting for at least 90 wt % of the ceramic composite.

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.

There is provided at least any of a layered body which has a change in color tone and in which it is unnecessary to select a colorant and the content of the colorant in consideration of a difference in the sintering behavior between layers, a precursor thereof, or a method for producing these. Provided is a layered body which has a structure, in which two or more layers containing stabilizer-containing zirconia and a colorant are layered, and in which types and contents of the colorants contained in the layers are equal to each other, the layered body including at least: a first layer containing a colorant and zirconia which has a stabilizer content of higher than or equal to 3.3 mol %; and a second layer containing a colorant and zirconia which has a stabilizer content different from that of the zirconia contained in the first layer.

A method for improving the Bs of an MnZn power ferrite material by moving the valley point includes the following steps: 1) mixing Fe.sub.2O.sub.3, MnO and ZnO, and performing primary sanding; 2) adding glue, performing spraying and granulating, and then performing pre-sintering to obtain a pre-sintered material; 3) adding additives to the pre-sintered material, and performing secondary sanding; and 4) adding glue to the secondary sanded material, performing spraying and granulating, pressing into a standard ring, and then performing sintering. The method controls and moves the valley point, reduces loss and improves the Bs of a material by controlling the Fe.sub.2O.sub.3 content and the Co.sub.2O.sub.3 content, and the method is relatively simple and suitable for industrialization.

An alumina-ceramic-based electrical insulator, to a method for producing the insulator, and to a vacuum tube includes the insulator. The electrical insulator is for insulating two electrodes of a vacuum tube through which a charged particle beam flows, the electrical insulator being formed of an alumina-based ceramic. The ceramic comprises a vitreous phase of between 2% and 8% by weight into which at least one metal oxide is diffused from a face of the electrical insulator.

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 method of producing a core-shell particle includes introducing a barium titanate-based base powder and an additive to a reactor, and exposing the barium titanate-based base powder and the additive to a thermal plasma torch to obtain core-shell particles including a core portion having barium titanate (BaTiO.sub.3) and a shell portion including the additive and formed on a surface of the core portion.

The present invention relates to a ceramic, to a process for preparing the ceramic and to the use of the ceramic as a dielectric in a capacitor.

The present invention provides a method of preparing bulk BSCCO-based material, the method comprising: mixing a first solution with a second solution at a pre-determined temperature to form a gel, wherein the first solution comprises salts of at least bismuth, strontium, calcium and copper and the second solution comprises a precipitating agent; drying the gel to form a xerogel; grinding the xerogel to form a homogeneous metalorganic precursor; and calcining the homogeneous metalorganic precursor to form bulk BSCCO-based materials. Further steps may enable preparation of 2D BSCCO flakes.