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)

0.360w=0.420(2)

0.110x0.173(3)

8.51z9.71(4)

0.208m0.269(5)

A method for producing a ceramic complex includes: preparing a raw material mixture that contains 5% by mass or more and 40% by mass or less of first rare earth aluminate fluorescent material particles containing an activating element and a first rare earth element different from the activating element, 0.1% by mass or more and 32% by mass or less of oxide particles containing a second rare earth element, and the balance of aluminum oxide particles, relative to 100% by mass of the total amount of the first rare earth aluminate fluorescent material particles, the oxide particles, and the aluminum oxide particles; preparing a molded body of the raw material mixture; and obtaining a sintered body by calcining the molded body in a temperature range of 1,550 C. or higher and 1,800 C. or lower.

The invention relates to a copper-ceramic substrate comprising: a ceramic carrier, and at least one copper layer bonded to a surface of the ceramic carrier, which has a free surface for forming a conductor structure and/or for securing bonding wires, wherein the copper layer has a microstructure with an average grain size diameter of 200 to 500 m, preferably 300 to 400 m.

A method for producing an alumina sintered body, including: a step of applying an alkaline earth metal compound onto a surface of an alumina raw material which is an unsintered alumina compact or an alumina sintered body; and a step of subjecting the alumina raw material to which the alkaline earth metal compound has been applied to heat treatment at a temperature of 1200 C. or more for 5 minutes or more and 300 minutes or less.

A ceramic electronic component includes: a ceramic body that includes internal electrodes; and an external electrode that includes a plurality of crystal particles containing Ba, Zn, Si, and O, the external electrode being formed on a surface of the ceramic body and connected to the internal electrodes.

A sintered MnZn ferrite body containing main components comprising 53.30-53.80% by mol of Fe calculated as Fe.sub.2O.sub.3, 6.90-9.50% by mol Zn calculated as ZnO, and the balance of Mn calculated as MnO, and sub-components comprising 0.003-0.020 parts by mass of Si calculated as SiO.sub.2, more than 0 parts and 0.35 parts or less by mass of Ca calculated as CaCO.sub.3, 0.30-0.50 parts by mass of Co calculated as Co.sub.3O.sub.4, 0.03-0.10 parts by mass of Zr calculated as ZrO.sub.2, and 0-0.05 parts by mass of Ta calculated as Ta.sub.2O.sub.5, pre 100 parts by mass in total of the main components (calculated as the oxides), and having an average crystal grain size of 3 m or more and less than 8 m and a density of 4.65 g/cm.sup.3 or more.

A nuclear fuel includes uranium(IV) oxide (UO.sub.2) and manganese (Mn) as a dopant. The Mn dopant may be present in the fuel in an amount up to the solubility limit for Mn under a given set of conditions, for example, about 0.01 wt % to about 1 wt %. The nuclear fuel is substantially free of aluminum (Al). The nuclear fuel exhibits enhanced grain size development during sintering temperatures as low at 1400 K due to an increase in uranium sub-lattice vacancies induced by dissolution of the Mn dopant at interstitial defect sites. The Mn-doped nuclear fuel exhibits improved grain sizes at lower temperatures compared to Cr-, Al-, and undoped UO.sub.2, and therefore desirably exhibits lower fission gas release and higher plasticity, reducing the chances of fuel rod failure.

Disclosed is a plastic semiconductor material and a preparation method thereof. The semiconductor material comprises an argentite-based compound represented by the following formula (I): Ag.sub.2-X.sub.S.sub.1-Y.sub.(I), in which 0<0.5, 0<0.5, Xis at least one of Cu, Au, Fe, Co, Ni, Zn, Ti, or V, and Y is at least one of N, P, As, Sb, Se, Te, O, Br, Cl, I, or F. The material can withstand certain deformations, similar to organic materials, and has excellent semiconductor properties with adjustable electrical properties, thereby enabling the preparation of high-performance flexible semiconductor devices.

An alumina sintered body including an inner layer in which alumina crystal grains contained have an average aspect ratio of 1.0 to 2.0 and an outer layer which covers at least a part of the inner layer from outside and in which alumina crystal grains contained have an average aspect ratio of more than 2.0, the alumina sintered body being free from silicon except unavoidable impurities.

A piezoelectric composition comprises a plurality of crystal particles, wherein the piezoelectric composition includes bismuth, iron, barium, titanium, and oxygen; the crystal particles include a core and a shell covering the core; the average value of the contents of bismuth in the cores is expressed as C.sub.CORE % by mass, the average value of the contents of bismuth in the shells is expressed as C.sub.SHELL % by mass, and the C.sub.CORE is lower than the C.sub.SHELL; and the number of all the particles comprised in the piezoelectric composition is expressed as N, the number of the crystal particles including the core and the shell is expressed as n, and n/N is 0.10 to 1.00.