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.

An NTC compound, a thermistor and a method for producing a thermistor are disclosed. In an embodiment an NTC compound includes a ceramic material of a MnNiO system as a main constituent, wherein the MnNiO system has a general composition Ni.sub.xMn.sub.2O.sub.4-, wherein y corresponds to a molar fraction of Ni of a total metal content of the ceramic material of the MnNiO system, which is defined as c(Ni):(c(Ni)+c(Mn)), and wherein the following applies: 0.500<x<0.610 and 0.197<y<0.240.

Disclosed are a pseudo-ternary thermoelectric material, a method of manufacturing the pseudo-ternary thermoelectric material, a thermoelectric element, and a thermoelectric module. The pseudo-ternary thermoelectric material includes bismuth (Bi), antimony (Sb), tellurium (Te), and selenium (Se), and a composition ratio thereof is Bi.sub.xSb.sub.2-xTe.sub.3 in which 0.3x0.6 or (Bi.sub.2Te.sub.3).sub.1-x-y(Sb.sub.2Te.sub.3).sub.x(Sb.sub.2Se.sub.3).sub.y in which 0<x<1 and 0.001y0.05.

A high-purity calcium carbonate sintered body containing less impurities and available for biological and like applications, a production method, a high-purity calcium carbonate porous sintered body containing less impurities and available for biological and like applications, and a production method. A method for producing a high-purity calcium carbonate sintered body includes the steps of: compaction molding calcium carbonate with a purity of 99.7% by mass or more to make a green body; and sintering the green body to produce a calcium carbonate sintered body. A method for producing a high-purity calcium carbonate porous sintered body according to the present invention includes the steps of: preparing a dispersion liquid containing calcium carbonate with a purity of 99.7% by mass or more; adding a foaming agent to the dispersion liquid, followed by stirring until foamy to make a foam; and sintering the foam to produce a calcium carbonate porous sintered body.

An active material for a fluoride ion secondary battery includes a composite fluoride which contains: an alkali metal or NH.sub.4; a transition metal; and fluorine.

Embodiments disclosed herein relate to using cobalt (Co) to fine tune the magnetic properties, such as permeability and magnetic loss, of nickel-zinc ferrites to improve the material performance in electronic applications. The method comprises replacing nickel (Ni) with sufficient Co.sup.+2 such that the relaxation peak associated with the Co.sup.+2 substitution and the relaxation peak associated with the nickel to zinc (Ni/Zn) ratio are into near coincidence. When the relaxation peaks overlap, the material permeability can be substantially maximized and magnetic loss substantially minimized. The resulting materials are useful and provide superior performance particularly for devices operating at the 13.56 MHz ISM band.

A ceramic waveguide includes: a doped metal oxide ceramic core layer; and at least one cladding layer comprising the metal oxide surrounding the core layer, such that the core layer includes an erbium dopant and at least one rare earth metal dopant being: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, thulium, ytterbium, lutetium, scandium, or oxides thereof, or at least one non-rare earth metal dopant comprising zirconium or oxides thereof. Also included is a quantum memory including: at least one doped polycrystalline ceramic optical device with the ceramic waveguide and a method of fabricating the ceramic waveguide.

A ferrite composition is provided containing Ba, Co, and Ir and having a Z-type hexaferrite phase and a Y-type hexaferrite phase. The ferrite composition has the formula Ba.sub.3Co.sub.(2+x)Ir.sub.xFe.sub.(24-2x)O.sub.41 where x=0.05-0.20. The composition has equal or substantially equal values of permeability and permittivity while retaining low magnetic and dielectric loss factors. The composition is suitable for ultrahigh frequency applications such as high frequency and microwave antennas.

A perovskite ceramic composition that contains Sn, Ba, and Ti, and where the Sn content is within a range of about 0.001 parts by molSnabout 0.999 parts by mole with respect to 100 parts by mole of the Ti. The perovskite ceramic composition can be used in a composition that further includes a rare earth element R, Mn, and Si, and optionally Mg, where proportions of the R, the Mn, the Si, and the optional Mg, satisfy R: 0<Rabout 10 parts by mole, Mn: 0<Mnabout 5 parts by mole, Si: 0<Siabout 5 parts by mole Mg: 0<Mgabout 5 parts by mole with respect to 100 parts by mole of Ti.

A solid electrolyte body for a gas sensor element constituted by solid electrolyte particles made of zirconia containing a stabilizer has a solid electrolyte phase in which a large number of the solid electrolyte particles are aggregated, and, in the solid electrolyte phase, pairs of the solid electrolyte particles adjoining each other do not have a particle interface impurity layer between their particle interfaces, and the particle interfaces directly contact with each other.