The disclosed technology relates to a ceramic composition and an article formed therefrom. A ceramic article for radio frequency applications is formed of a ceramic material having a chemical formula represented by: Bi.sub.1.0+aY.sub.2.0-a-x-2yCa.sub.x+2yFe.sub.5-x-yM.sup.IV.sub.xV.sub.yO.sub.12 or Bi.sub.1.0+aY.sub.2.0-a-2yCa.sub.2yFe.sub.5-y-zV.sub.yIn.sub.zO.sub.12. The ceramic material has a composition such that a normalized change in saturation magnetization (Δ4πMs), defined as Δ4πMs=[(4πMs at 20° C.)-(4πMs at 120° C.)]/(4πMs at 20° C.), is less than about 0.35.

A ceramic electronic device includes a multilayer chip in which each of a plurality of dielectric layers and each of a plurality of internal electrode layers including Ni as a main phase are alternately stacked. At least one of the plurality of dielectric layers includes a secondary phase including Si, at an interface between the at least one of the plurality of dielectric layers and one of the plurality of internal electrode layers next to the at least one of the plurality of dielectric layers. The one of the plurality of internal electrode layers includes a layer including an additive element including one or more of Au, Pt, Cu, Fe, Cr, Zn, and In, at a region contacting the secondary phase at the interface.

A ferrite sintered magnet comprises a plurality of main phase grains containing a ferrite having a hexagonal structure, wherein at least some of the main phase grains are core-shell structure grains each having a core and a shell covering the core; and wherein the minimum value of the content of La in the core is [La]c atom %; the minimum value of the content of Co in the core is [Co]c atom %; the maximum value of the content of La in the shell is [La]s atom %; the maximum value of the content of Co in the shell is [Co]s atom %; [La]c+[Co]c is 3.08 atom % or more and 4.44 atom % or less; and [La]s+[Co]s is 7.60 atom % or more and 9.89 atom % or less.

To form, on a ceramic member or a metal member, a thermal spray ceramic coating film which achieves both the quality of a ceramic coating film and gas barrier property, and with which a composite oxide having a melting point lower than the ambient temperature will not form when used as a coating film on a ceramic member or a metal member constituting a glass article manufacturing apparatus. A ceramic coating film-provided member comprising a ceramic member or a metal member and a thermal spray ceramic coating film formed on at least a part of the surface of the ceramic member or the metal member, wherein the thermal spray ceramic coating film contains Al.sub.2O.sub.3 and 12CaO.7Al.sub.2O.sub.3, and the weight ratio of CaO to Al.sub.2O.sub.3 (CaO/Al.sub.2O.sub.3) is more than 0.11 to 0.50.

A ceramic contains, in mass percent: Si.sub.3N.sub.4: 20.0 to 60.0%, ZrO.sub.2: 25.0 to 70.0%, and one or more oxides selected from MgO, Y.sub.2O.sub.3, CeO.sub.2, CaO, HfO.sub.2, TiO.sub.2, Al.sub.2O.sub.3, SiO.sub.2, MoO.sub.3, CrO, CoO, ZnO, Ga.sub.2O.sub.3, Ta.sub.2O.sub.5, NiO, and V.sub.2O.sub.5: 5.0 to 15.0%. The ceramic has a coefficient of thermal expansion as high as that of silicon and an excellent mechanical strength, allows fine machining with high precision, and prevents particles from being produced.

Disclosed is a polycrystalline ceramic dielectric comprising: crystal grain bulks made of a barium titanate-based ceramic; and grain boundaries comprising interfaces between the crystal grain bulks, wherein the composition of the grain boundaries is controlled using dopants. By controlling the grain boundary composition using dopants so that the dopants are distributed across a width of 5 nm or less and using a nano-sized, fine-grained barium titanate-based ceramic precursor, the grain boundary structure within the polycrystals may maintain electroneutrality, and their ferroelectricity may be controlled, thereby allowing for smoother polarization reaction. Accordingly, the present disclosure provides polycrystalline ceramic dielectrics that have dielectric properties such as high permittivity and low dielectric losses in a wide frequency range, a small amount of reduction in electric field-dependent relative permittivity, high temperature stability, non-reducibility under a reduction sintering condition, and resulting high insulation resistance, and a preparation method therefor.

The present invention provides a ferrite sintered magnet comprising ferrite crystal grains having a hexagonal structure, wherein the ferrite sintered magnet comprises metallic elements at an atomic ratio represented by formula (1). In formula (1), R is at least one element selected from the group consisting of Bi and rare-earth elements, and R comprises at least La. In formula (1), w, x, z and m satisfy formulae (2) to (5). The above-mentioned ferrite sintered magnet further has a coefficient of variation of a size of the crystal grains in a section parallel to a c axis of less than 45%.
Ca.sub.1-w-xR.sub.wSr.sub.xFe.sub.zCo.sub.m  (1)
0.360≤w≤0.420  (2)
0.110≤x≤0.173  (3)
8.51≤z≤9.71  (4)
0.208≤m≤0.269  (5)

Provided are a method for preparing a gel composite material with a piezoelectric property, and the gel composite material and use thereof, which belongs to the field of intelligent road traffic. In the method, titanium-containing blast furnace slag and metal oxides (PbO and ZrO.sub.2) are sufficiently and uniformly mixed, an obtained mixture is calcined under a certain thermal system, on the theoretical basis of mineral-phase reconstruction-synergistic regulation of all valuable components, and the mixture is cooled to a room temperature with a furnace to obtain the gel composite material with a piezoelectric property.

Provided is a boron nitride sintered body including boron nitride particles and pores, the boron nitride sintered body having a sheet shape and a thickness of less than 2 mm. Provided is a method for manufacturing a boron nitride sintered body, the method including a sintering step of molding and heating a blend containing a boron carbonitride powder and a sintering aid to obtain a sheet-shaped boron nitride sintered body including boron nitride particles and pores, in which a thickness of the boron nitride sintered body obtained in the sintering step is less than 2 mm.

A ceramic powder material containing: a first garnet-type compound containing Li, La, and Zr; and a second garnet-type compound containing Li, La, and Zr and having a composition different from a composition of the first garnet-type compound, in which the first garnet-type compound and the second garnet-type compound are represented by Formula [1] Li.sub.7-(3x+y)M1.sub.xLa.sub.3Zr.sub.2-yM2.sub.yO.sub.12, where Ml is Al or Ga, M2 is Nb or Ta, the first garnet-type compound satisfies 0≤(3x+y)≤0.5, and the second garnet-type compound satisfies 0.5<(3x+y)≤1.5.