The present application discloses a dense lead metaniobate piezoelectric ceramic and a preparation method therefor. The chemical composition of the lead metaniobate piezoelectric ceramic is Pb.sub.1-xNb.sub.2O.sub.6, wherein x represents the Pb vacancy concentration of A sites in a tungsten bronze crystal structure, and x is greater than 0.00 and smaller than or equal to 0.20.

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 zirconia sintered body is provided and includes yttria and zirconia, containing yttria by a content ranging from 4.5 mol % or more to 6.5 mol % or less and zirconia as the remainder, the total light transmittance of a 1-mm thick sample measured in compliance with JIS K 7361-1 being 46.5% or higher, the three-point bending strength being 700 MPa or higher, and a ratio of an integrated value for the total light transmittance to an integrated value for the parallel light transmittance of a 1-mm thick sample measured at the measurement wavelength ranging from 400 to 700 nm being 1.3% or less.

A sintered bead with the following crystal phases, in percentages by mass based on crystal phases: 25%≤zircon, or “Z.sub.1”, ≤94%; 4%≤stabilized zirconia+stabilized hafnia, or “Z.sub.2”, ≤61%; monoclinic zirconia+monoclinic hafnia, or “Z.sub.3”≤50%; corundum≤57%; crystal phases other than Z.sub.1, Z.sub.2, Z.sub.3 and corundum<10%; the following chemical composition, in percentages by mass based on oxides: 33%≤ZrO.sub.2+HfO.sub.2, or “Z.sub.4”≤83.4%; HfO.sub.2≤2%; 10.6%≤SiO.sub.2≤34.7%; Al.sub.2O.sub.3≤50%; 0%≤Y.sub.2O.sub.3, or “Z.sub.5”; 0%≤CeO.sub.2, or “Z.sub.6”; 0.3%≤CeO.sub.2+Y.sub.2O.sub.3≤19%, provided that (1) CeO.sub.2+3.76*Y.sub.2O.sub.3≥0.128*Z, and (2) CeO.sub.2+1.3*Y.sub.2O.sub.3≤0.318*Z, with Z=Z.sub.4+Z.sub.5+Z.sub.6−(0.67*Z.sub.1*(Z.sub.4+Z.sub.5+Z.sub.6)/(0.67*Z.sub.1+Z.sub.2+Z.sub.3)); MgO≤5%; CaO≤2%; oxides other than ZrO.sub.2, HfO.sub.2, SiO.sub.2, Al.sub.2O.sub.3, MgO, CaO, CeO.sub.2 and Y.sub.2O.sub.3<5.0%.

A process for the manufacture of a refractory block including more than 80% zirconia, in percentage by weight based on the oxides. The process includes the following successive stages: melting, under reducing conditions, of a charge including more than 50% zircon, in percentage by weight, such as to reduce the zircon and obtain a molten material, application of oxidizing conditions to the molten material, casting of the molten material, and cooling until at least partial solidification of the molten material in the form of a block. Also, the process can include heat treatment of the block.

A dielectric composition includes a main phase and a Ca—Si—P—O segregation phase. The main phase includes a main component expressed by ABO.sub.3. “A” includes at least one selected from calcium and strontium. “B” includes at least one selected from zirconium, titanium, hafnium, and manganese. The Ca—Si—P—O segregation phase includes at least calcium, silicon, and phosphorus.

The present invention relates to a nitrogen-doped sulfide-based solid electrolyte for all-solid batteries. The a nitrogen-doped sulfide-based solid electrolyte for all-solid batteries includes a compound with an argyrodite-type crystal structure represented by the following Formula 1:
Li.sub.aPS.sub.bN.sub.cX.sub.d  [Formula 1] wherein 6≤a≤7, 3<b<6, 0<c≤1, 0<d≤2, and each X is the same or different halogen atom selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I).

Provided is a piezoelectric ceramics including crystal grains each including: a first region that is formed of a perovskite-type metal oxide having a crystal structure in which a central element of a unit cell is located at an asymmetrical position; and a second region that is formed of a perovskite-type metal oxide having a crystal structure in which a central element of a unit cell is located at a symmetrical position, and that is present inside the first region, wherein a ratio of a cross-sectional area of the second region to a cross-sectional area of the piezoelectric ceramics is 0.1% or less.

A dielectric substance includes a core-shell grain having a twin crystal structure. An interface of the twin crystal structure of the core-shell grain extends from a shell on one side, passes through a core, and extends to the shell on the other side.

A sintered bead and an associated method. The sintered bead has the following chemical composition, as mass percentages on the basis of the oxides: ZrO.sub.2+HfO.sub.2+Y.sub.2O.sub.3+CeO.sub.2: remainder to 100%; 0%≤Al.sub.2O.sub.3≤1.5%; CaO≤2%; oxides other than ZrO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, CeO.sub.2, Al.sub.2O.sub.3 and CaO: ≤5%. The contents of Y.sub.2O.sub.3 and CeO.sub.2, as molar percentages on the basis of the sum of ZrO.sub.2, HfO.sub.2, Y.sub.2O.sub.3 and CeO.sub.2, being such that 1.8%≤Y.sub.2O.sub.3≤2.5% and 0.1%≤CeO.sub.2≤0.9%. The sintered bead has following crystalline phases, as mass percentages on the basis of the crystalline phases and for a total of 100%: stabilized zirconia: remainder to 100%; monoclinic zirconia: ≤10%; crystalline phases other than stabilized zirconia and monoclinic zirconia: <7%.