A dielectric composition includes one of BaTiO.sub.3, (Ba,Ca) (Ti,Ca)O.sub.3, (Ba,Ca) (Ti,Zr)O.sub.3, Ba(Ti,Zr)O.sub.3 and (Ba,Ca) (Ti,Sn)O.sub.3, as a main component, a first subcomponent including a rare earth element, and a second subcomponent including at least one of a variable valence acceptor element and a fixed valence acceptor element. When a sum of contents of the rare earth element is defined as DT and a sum of contents of the variable valence acceptor element and the fixed valence acceptor element is defined as AT, (DT/AT)/(Ba+Ca) satisfies more than 0.5 and less than 6.0. In addition, a multilayer electronic component including the dielectric composition is provided.

An electro-conductive B.sub.4C—TiB.sub.2 has a microstructure in which large B.sub.4C grains are coated by small TiB.sub.2 grains. The composite ceramic includes 10˜30% by volume of TiB.sub.2. A method for preparing the electro-conductive B.sub.4C—TiB.sub.2 composite ceramic includes: (1) weighing B.sub.4C, TiC, and amorphous B powder; (2) mixing evenly and drying thoroughly the powders; and (3) loading the mixed powder into a graphite mold; and placing the graphite mold in a spark plasma sintering furnace for sintering under vacuum, where the sintering is performed at 2000° C. and 50 MPa for 5˜20 min.

A cBN sintered compact comprising a cubic boron nitride and a ceramic binder phase, wherein a cubic C-containing Ta compound in an amount of 1.0 to 15.0 vol % is dispersed in the ceramic binder phase and has a mean particle diameter of 50 to 500 nm.

A zirconia sintered body may excel in translucency, strength, and linear light transmittance with no use of an HIP device, and a zirconia molded body and a zirconia pre-sintered body from which such a zirconia sintered body can be obtained. A zirconia molded body may include zirconia particles with 2.0 to 9.0 mol % yttria, an average primary particle diameter of 60 nm or less, and 0.5 mass % or less zirconia particles having a particle diameter >100 nm, wherein the zirconia molded body has ΔL*(W−B) of 5+ through a thickness of 1.5 mm. A zirconia pre-sintered body may include 2.0 to 9.0 mol % yttria, and have a ΔL*(W−B) of 5+ through a thickness of 1.5 mm. A zirconia sintered body may include: a fluorescent agent; 2.0 to 9.0 mol % yttria, and have a linear light transmittance of 1% or more through a thickness of 1.0 mm.

Provided is a method for producing a calcium carbonate sintered body whereby a good sintered body can be obtained without having to use any sintering aid. A method for producing a calcium carbonate sintered body includes the steps of: compacting calcium carbonate to make a green body; heating the green body under a condition of a temperature of 500° C. or lower to remove an organic component contained in the green body; and sintering the green body under conditions of a carbon dioxide atmosphere and a temperature of 450° C. or higher to obtain a calcium carbonate sintered body.

A ferrite sintered magnet has a ferrite phase having a magnetoplumbite-type crystal structure, and contains at least a metal element A, a metal element R, Fe, Co, Zn, and B. The element A is at least one kind of element selected from the group consisting of Sr, Ba, Ca, and Pb, and essentially includes Ca. The element R is at least one kind of element selected from the group consisting of Bi and rare-earth elements including Y, and essentially includes La. Atomic ratios of the metal elements satisfy the following expressions.

A.sub.1-rR.sub.rFe.sub.xCo.sub.yZn.sub.z  (1)

0.40≤r≤0.70  (2)

8.20≤x≤9.34  (3)

0.05<y≤0.50  (4)

0<z≤0.20  (5)

The content of Si is 0 to 0.60% by mass in terms of SiO.sub.2, and the content of B is 0.01 to 0.70% by mass in terms of B.sub.2O.sub.3.

A cubic boron nitride sintered material includes: more than or equal to 80 volume % and less than or equal to 96 volume % of cubic boron nitride grains; and a binder, wherein the binder includes tungsten carbide, cobalt, and an aluminum compound, and Ha/Hb≥0.40 is satisfied, where Hb represents a hardness of the cubic boron nitride sintered material and Ha represents a hardness of the cubic boron nitride sintered material after performing acid treatment onto the cubic boron nitride sintered material to substantially remove the binder in the cubic boron nitride sintered material.

One aspect of the present invention is a multilayer ceramic capacitor including a plurality of dielectric layers composed of a dielectric ceramic containing grains whose main component is barium titanate having a core-shell structure made up of a core part and a shell part, and grains whose main component is calcium titanate having a core-shell structure made up of a core part and a shell part; and a plurality of internal electrodes stacked alternately with each of the plurality of dielectric layers.

A novel metal oxide or a novel sputtering target is provided. A sputtering target includes a conductive material and an insulating material. The insulating material includes an oxide, a nitride, or an oxynitride including an element M1. The element M1 is one or more kinds of elements selected from Al, Ga, Si, Mg, Zr, Be, and B. The conductive material includes an oxide, a nitride, or an oxynitride including indium and zinc. A metal oxide film is deposited using the sputtering target in which the conductive material and the insulating material are separated from each other.

A tungsten carbide powder 1 includes bonded bodies 10 each including a plurality of tungsten carbide crystal grains 11, in which the bonded bodies 10 include, at a grain boundary 11a between the plurality of tungsten carbide crystal grains 11, a chromium-concentrated region 12 which has a chromium concentration higher than that in the tungsten carbide crystal grains 11.