A method that enables fabrication of a machinable zirconia composite sintered body that is machinable in a sintered state while maintaining properties suited for dental use, in a shorter time than it is possible with conventional methods. A method for producing a machinable zirconia composite sintered body by fabricating a molded body with a raw material composition that includes 78 to 95 mol % of ZrO.sub.2 and 2.5 to 10 mol % of Y.sub.2O.sub.3, and also includes 2 to 8 mol % of Nb.sub.2O.sub.5 and/or 3 to 10 mol % of Ta.sub.2O.sub.5, and in which ZrO.sub.2 predominantly includes a monoclinic crystal system and sintering the molded body.

The present invention provides a silicon-silicon composite oxide-carbon composite, a method for preparing same, and a negative electrode active material for a lithium secondary battery, comprising same. More particularly, the silicon-silicon composite oxide-carbon composite of the present invention has a core-shell structure wherein the core comprises silicon, a silicon oxide compound, and magnesium silicate, and the shell comprises a carbon layer. In addition, by having a specific range of span values through the adjustment of particle size distribution of the composite, when used as a negative electrode active material of a secondary battery, the composite can improve not only the capacity of the secondary battery but also the cycle characteristics and initial efficiency thereof.

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.

A multilayer ceramic capacitor (10) has a laminate body (20) constituted by dielectric layers (17) and internal electrode layers (18) stacked alternately. The dielectric layers (17) contain (Ba.sub.(1-x-y)Ca.sub.xSr.sub.y).sub.m(Ti.sub.(1-z)Zr.sub.z)O.sub.3, where 0.03≤x≤0.16, 0≤y≤0.02, 0<z≤0.02, 0.99≤m≤1.02, as a primary component, and an R oxide (R is a rare earth element) by 1.0 to 4.0 mol in equivalent element, an Mg compound by 0.2 to 2.5 mol in equivalent element, an Mn compound by 0.1 to 1.0 mol in equivalent element, a Zr compound by 0.1 to 2.0 mol in equivalent element, a V compound by 0.05 to 0.3 mol in equivalent element, and an Si compound by 0.2 to 5.0 mol in equivalent element, per 100 mol of the primary component. The multilayer ceramic capacitor can offer excellent DC bias properties and ensure high reliability.

A multilayer electronic component includes a multilayer body including dielectric layers and inner electrode layers, the multilayer body including an electrode facing portion in which the inner electrode layers are laminated to face each other with the dielectric layers interposed therebetween. The multilayer body has a thickness of at least about 1.5 mm in a lamination direction, a length of at least about 3.0 mm, and a width of at least about 1.5 mm. Each of the dielectric layers includes Ba, Ti, and Cl. A Cl concentration C.sub.1 in the entire electrode facing portion satisfies about 10 wtppm<C.sub.1<about 50 wtppm. On an imaginary central axis line, a Cl concentration C.sub.2 in a central portion of the electrode facing portion and a Cl concentration C.sub.3 in both end portions of the electrode facing portion satisfy about 0.5C.sub.2≤C.sub.3<C.sub.2.

Coated zirconia fine particle containing a zirconia fine particle and a coating layer coating the surface of the fine particle. The coating layer includes one or more metal elements selected from Mg, Ca, Al and rare-earth elements, and the coated zirconia fine particle has an average particle size of 3 to 100 nm and a specific surface area of 20 to 500 m.sup.2/g.

A capacitor component includes: a body including a dielectric layer and an internal electrode layer; and an external electrode disposed on the body, and connected to the internal electrode layer. A surface color of the body is R≤30, G≤30, B≤40 based on R/G/B, and a dielectric constant of the dielectric layer is 2000 or more and 4000 or less.

A cubic boron nitride sintered material includes: more than or equal to 50 volume % and less than 80 volume % of cubic boron nitride grains; and more than 20 volume % and less than or equal to 50 volume % of a binder phase, and when an oxygen content is measured in a direction perpendicular to an interface between cubic boron nitride grains using TEM-EDX, a first region having an oxygen content larger than an average value of an oxygen content of a cubic boron nitride grain exists, the interface exists in the first region, and a length of the first region along the direction perpendicular to the interface is more than or equal to 0.1 nm and less than or equal to 10 nm.

The invention relates to a ceramic material, comprising lead zirconate titanate, which additionally contains K and optionally Cu. The ceramic material can be used in an electroceramic component, for example a piezoelectric actuator. The invention also relates to methods for producing the ceramic material and the electronic component.

The present invention provides a high thermal conductive silicon nitride sintered body having a thermal conductivity of 50 W/m.Math.K or more and a three-point bending strength of 600 MPa or more, wherein when an arbitrary cross section of the silicon nitride sintered body is subjected to XRD analysis and highest peak intensities detected at diffraction angles of 29.3±0.2°, 29.7±0.2°, 27.0±0.2°, and 36.1±0.2° are expressed as I.sub.29.3°, I.sub.29.7°, I.sub.27.0°, and I.sub.36.1°, a peak ratio (I.sub.29.3°)/(I.sub.27.0°+I.sub.36.1°) satisfies a range of 0.01 to 0.08, and a peak ratio (I.sub.29.7°)/(I.sub.27.0°+I.sub.36.1°) satisfies a range of 0.02 to 0.16. Due to above configuration, there can be provided a silicon nitride sintered body having a high thermal conductivity of 50 W/m.Math.K or more, and excellence in insulating properties and strength.