The ceramic material element includes a main phase of orthorhombic perovskite-structure and a secondary phase due to a heat treatment within 700° C. to 850° C. for a first period followed by a second period within 1140° C. to 1170° C., from a mixture of materials A1, A2, A3, A4 and A5 excluding lead, the materials A1, A2, A3, A4 and A5 having molar ratios R1, R2, R3, R4 and R5, respectively, where the material A1 comprises potassium, the material A2 comprises sodium, the material A3 comprises barium, the material A4 comprises niobium, and the material A5 comprises nickel, and the molar ratio R1 is in a range 0.29-0.32, the molar ratio R2 is in a range 0.20-0.23, the molecular ratio R3 is in a range 0.01-0.02, the molar ratio R4 is in a range 0.54-0.55, and the molar ratio R5 is in a range 0.006-0.011, while a relative ratio of R1/R2 is in the range 1.24-1.52, and a relative ratio of R4/R2 is in the range 2.32-2.62. The ceramic material element converts optical radiation energy and mechanical vibration energy into electric energy.

A refractory object may include a zircon body that may include at least about 0.1 wt. % and not greater than about 5.5 wt. % of an Al.sub.2O.sub.3 containing component for a total weight of the zircon body. The zircon body may further include at least about 25 wt. % and not greater than about 35 wt. % of a SiO.sub.2 component for a total weight of the zircon body.

A negative electrode material for lithium ion secondary batteries, the negative electrode material including particles (A) containing an element capable of occluding/releasing lithium ions other than a carbon element; graphite particles (B) capable of occluding/releasing lithium ions and having a median value of not smaller than 1.4 and not larger than 3.0 in a number-based distribution of aspect ratios of primary particles and carbon fibers (C); wherein a three dimensional web structure is formed from one or more carbon fibers (C), the particles (A) are fusion-bonded to the structure, and the structure is fusion-bonded to at least a part of a surface of the graphite particle (B). Also disclosed is a lithium ion secondary battery obtained using the negative electrode material.

A method of making a polycrystalline cubic boron nitride (PCBN), material is provided. The matrix precursor powder comprises an aluminium compound. The method comprises mixing matrix precursor powder comprising particles having an average particle size no greater than 250 nm, with between 30 and 40 volume percent of cubic boron nitride (cBN) particles having an average particle size of at least 4 μm, and then spark plasma sintering the mixed particles. The spark plasma sintering occurs at a pressure of at least 500 MPa, a temperature of no less than 1050° C. and no more than 1500° C. and a time of no less than 1 minute and no more than 3 minutes.

Provided is a dielectric composition exhibiting a high strength and a high specific dielectric constant. The dielectric composition contains composite oxide particles having a composition formula represented by (Sr.sub.xBa.sub.1-x).sub.yNb.sub.2O.sub.5+y and an Al-based segregation phase. The Al segregation phase has niobium, aluminum, and oxygen.

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.

A transparent complex oxide sintered body is manufactured by sintering a compact in an inert atmosphere or vacuum, and HIP treating the sintered compact, provided that the compact is molded from a source powder based on a rare earth oxide: (Tb.sub.xY.sub.1-x).sub.2O.sub.3 wherein 0.4≤x≤0.6, and the compact, when heated in air from room temperature at a heating rate of 15° C./min, exhibits a weight gain of at least y % due to oxidative reaction, y being determined by the formula: y=2x+0.3. The sintered body has a long luminescent lifetime as a result of controlling the valence of Tb ion.

A ceramic material, including: BaWO.sub.4-xM.sub.2CO.sub.3-yBaO-zB.sub.2O.sub.3-wSiO.sup.2, where x=0-0.2 mole, y=0-0.05 mole, z=0-0.2 mole, w=0-0.1 mole, M represents an alkali metal ion selected from Li.sup.+, K.sup.+, Na.sup.+, and x, y, z, and w are not zero at the same time.

A cordierite-based sintered body according to the present invention contains cordierite as a main component and silicon nitride or silicon carbide. The cordierite-based sintered body preferably has a thermal expansion coefficient less than 2.4 ppm/° C. at 40° C. to 400° C., an open porosity of 0.5% or less, and an average grain size of 1 μm or less.

A ferrite sintered body of the invention includes; a main component including 48.65 to 49.45 mol % of iron oxide in terms of Fe.sub.2O.sub.3, 2 to 16 mol % of copper oxide in terms of CuO, 28.00 to 33.00 mol % of zinc oxide in terms of ZnO, and a balance including nickel oxide, and a subcomponent including boron oxide in an amount of 5 to 100 ppm in terms of B.sub.2O.sub.3 with respect to 100 parts by weight of the main component, in which the ferrite sintered body includes crystal grains having an average crystal grain size of 2 to 30 μm.