Ceramic particles for use in a solar power tower and methods for making and using the ceramic particles are disclosed. The ceramic particle can include a sintered ceramic material formed from a mixture of a ceramic raw material and a darkening component comprising MnO as Mn.sup.2+. The ceramic particle can have a size from about 8 mesh to about 170 mesh and a density of less than 4 g/cc.

A piezoelectric composition including copper and a complex oxide having a perovskite structure represented by a general formula ABO.sub.3, in which an A site element in the ABO.sub.3 is potassium or potassium and sodium, a B site element in the ABO.sub.3 is niobium or niobium and tantalum, the copper is included in n mol % in terms of a copper element with respect to 1 mol of the complex oxide, and n satisfies 0.100n1.000.

A manufacturing method of ceramic powder includes: synthesizing barium titanate powder from barium carbonate, titanium dioxide, manganese carbonate, and one of ammonium molybdate and tungsten oxide, wherein: a solid solution amount of the donor element is 0.05 mol or more and 0.3 mol or less; a solid solution amount of the accepter element with respect to the barium titanate is 0.02 mol or more and 0.2 mol or less on a presumption that the amount of the barium titanate is 100 mol and the acceptor element is converted into an oxide; and relationships y0.0003x+1.0106, y0.0002x+1.0114, 4x25 and y1.0099 are satisfied when a specific surface area of the ceramic powder is x and an axial ratio c/a of the ceramic powder is y.

A piezoelectric composition including manganese and a complex oxide having a perovskite structure represented by a general formula ABO.sub.3, wherein an A site element in the ABO.sub.3 is potassium or potassium and sodium, a B site element in the ABO.sub.3 is niobium, a concentration distribution of the manganese has a variation, and the variation shows a CV value of 35% or more and 440% or less.

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.4L.sub.5)/L.sub.50.05 and (L.sub.8L.sub.9)/L.sub.90.05 when the lengths of twelve BiO 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 0x0.2, 0y0.1, 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.

Slip for the production of ceramic or glass ceramic shaped parts by a LIFT process, which contains (a) ceramic and/or glass ceramic particles, (b) binder, (c) at least one energy transformation component and (d) at least one dispersant, as well as a LIFT process for the production of ceramic or glass ceramic shaped parts using the slip.

The invention relates to the field of environmental protection, more specifically to the field of processing radioactive waste, and can he used for the safe and effective handling of a large quantity of liquid radioactive waste of various activity levels that has been formed as the result of decontaminating protective equipment of boxes and chambers, and makes it possible to decrease the volume of stored waste by solidifying same and incorporating same into a ceramic matrix. For this purpose, radioactive solutions after decontamination of surfaces of protective equipment are evaporated as alkaline and acidic solutions containing sodium hydroxide, potassium permanganate, oxalic acid, and nitric acid until a solid residue forms, and are calcined, and the calcinate is mixed with components of a fusion mixture containing oxides of titanium, calcium, iron (III), zirconium, and manganese (IV) and aluminum in a specified ratio, and fused.

There is disclosed a piezoelectric ceramic having the composition: a[PbTiO.sub.3]-b[SrTiO.sub.3]-c[BiFeO.sub.3]-d[(K.sub.xBi.sub.1-x)TiO.sub.3]; wherein 0.4<x<0.6; 0.1<a<0.4; 0.01<b0.2; c0.05; d0.01; and a+b+c+d=1 optionally comprising an A- or B-site metal dopant in an amount of up to 2 at. %.

A ceramic material for a multilayer ceramic capacitor has a capacitance variation from 17 percent to +15 percent at a temperature ranging from 55 C. to 200 C., and has a dielectric loss less than 1% at a temperature ranging from 90 C. to 200 C. The ceramic material includes a base component consisting of a barium titanate and a sodium bismuth titanate, and a manganese dopant in an amount not greater than 0.05 mole percent based on total moles of the base component.

The present invention provides a piezoelectric material not containing lead and potassium, showing satisfactory insulation and piezoelectricity, and having a high Curie temperature. The invention relates to a piezoelectric material includes a main component containing a perovskite-type metal oxide represented by Formula (1): (Na.sub.xBa.sub.1-y)(Nb.sub.yTi.sub.1-y)O.sub.3 (wherein, 0.80x0.94 and 0.83y0.94), and an additive component containing at least one element selected from Mn and Ni, wherein the content of the Ni is 0 mol or more and 0.05 mol or less based on 1 mol of the perovskite-type metal oxide, and the content of the Mn is 0 mol or more and 0.005 mol or less based on 1 mol of the perovskite-type metal oxide.