Phosphors include a CaAlSiN.sub.3 family crystal phase, wherein the CaAlSiN.sub.3 family crystal phase comprises at least one element selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb.

The present invention provides a method of preparing bulk BSCCO-based material, the method comprising: mixing a first solution with a second solution at a pre-determined temperature to form a gel, wherein the first solution comprises salts of at least bismuth, strontium, calcium and copper and the second solution comprises a precipitating agent; drying the gel to form a xerogel; grinding the xerogel to form a homogeneous metalorganic precursor; and calcining the homogeneous metalorganic precursor to form bulk BSCCO-based materials. Further steps may enable preparation of 2D BSCCO flakes.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

A solid electrolyte which contains a garnet-type composite metal oxide phase (L) and shows an excellent lithium ion conductivity is provided. The solid electrolyte contains a garnet-type composite metal oxide phase (L) and a phase (D) different from the phase (L). The phase (L) contains Li, La, Zr, O, and Ga, and an Li site in the phase (L) is substituted with the Ga. A lattice constant of the solid electrolyte is not smaller than 12.96 Å. The phase (D) contains at least one of LiF, BaZrO.sub.3, YF.sub.3, SrF.sub.2, and ScF.sub.3.

An oxide-based solid electrolyte with a high lithium ion conductance is provided. A lithium ion-conducting garnet type oxide includes Li, La, Ga, Zr, a halogen element, and oxygen. A lithium ion conductivity at room temperature is not lower than 1.0×10.sup.−3 S/cm. A proportion of Ga with respect to 1 mole of the oxide may be not larger than 0.5 moles.

The halogen element may be at least one type selected from the group consisting of Cl, Br, and I, and a proportion of Li with respect to 1 mole of the oxide may be not smaller than 6.1 moles and smaller than 6.5 moles.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

Disclosed herein are compounds, methods, and tools which comprise composite matrices of tungsten tetraborides and ceramics.

A piezoelectric material including a perovskite-type metal oxide represented by the following general formula (1); Bi; and Mn, wherein the content of Bi is 0.1-0.5 mol % with respect to 1 mol of the metal oxide, the content of Mn is 0.3-1.5 mol % with respect to 1 mol of the metal oxide, and the piezoelectric material satisfies (L.sub.4−L.sub.5)/L.sub.5≧0.05 and (L.sub.8−L.sub.9)/L.sub.9≧0.05 when the lengths of twelve Bi—O bonds with Bi that is located at a 12-fold site with respect to O in a perovskite-type unit cell as a starting point are taken to be L.sub.1 to L.sub.12 in length order:

(Ba.sub.1-xM1.sub.x)(Ti.sub.1-yM2.sub.y)O.sub.3  (1)

wherein 0≦x≦0.2, 0≦y≦0.1, and M1 and M2 are mutually different metal elements which have a total valence of +6 and are selected from other elements than Ba, Ti, Bi and Mn.

A purification method that uses ion-selective ceramics to electrochemically filter waste products from a molten salt. The electrochemical method uses ion-conducting ceramics that are selective for the molten salt cations desired in the final purified melt, and selective against any contaminant ions. The method can be integrated into a slightly modified version of the electrochemical framework currently used in pyroprocessing of nuclear wastes.

Provided are a barium titanate-based piezoelectric ceramics having satisfactory piezoelectric performance and a satisfactory mechanical quality factor (Q.sub.m), and a piezoelectric element using the same. Specifically provided are a piezoelectric ceramics, including: crystal particles; and a grain boundary between the crystal particles, in which the crystal particles each include barium titanate having a perovskite-type structure and manganese at 0.04% by mass or more and 0.20% by mass or less in terms of a metal with respect to the barium titanate, and the grain boundary includes at least one compound selected from the group consisting of Ba.sub.4Ti.sub.12O.sub.27 and Ba.sub.6Ti.sub.17O.sub.40, and a piezoelectric element using the same.