A lead-free piezoelectric material includes perovskite-type metal oxide containing Na, Nb, Ba, Ti, and Mg and indicates excellent piezoelectric properties. The piezoelectric material satisfies the following relational expression (1): 0.430≤a≤0.460, 0.433≤b≤0.479, 0.040≤c≤0.070, 0.0125≤d≤0.0650, 0.0015≤e≤0.0092, 0.9×3e≤c−d≤1.1×3e, a+b+c+d+e=1, where a, b, c, d, and e denote the relative numbers of Na, Nb, Ba, Ti, and Mg atoms, respectively.

This document describes processes for preparing ceramics, especially lithium-based ceramics. The ceramics produced by this process and their use in electrochemical applications are also described as well as electrode materials, electrodes, electrolyte compositions, and electrochemical cells comprising them.

Embodiments relate to a piezoelectric ceramic and methods of making the same that is suitable for use as a high-power piezoelectric ceramic, and in particular a piezoelectric ceramic that exhibits both good hard properties and good soft properties. Embodiments involve generating the piezoelectric ceramic via the combination of chemical modification/doping and/or a texturing method so that the piezoelectric material exhibits a large figure of merit, as well as other hard and soft properties. The chemical modification involves Cu and Mn doping a piezoelectric material composition having a relaxor-lead titanate based ferroelectric structure. The texturing involves templated grain growth (TGG) texturing using a BaTiO.sub.3 (BT) template.

Embodiments relate to a piezoelectric ceramic and methods of making the same that is suitable for use as a high-power piezoelectric ceramic, and in particular a piezoelectric ceramic that exhibits both good hard properties and good soft properties. Embodiments involve generating the piezoelectric ceramic via the combination of chemical modification/doping and/or a texturing method so that the piezoelectric material exhibits a large figure of merit, as well as other hard and soft properties. The chemical modification involves Cu and Mn doping a piezoelectric material composition having a relaxor-lead titanate based ferroelectric structure. The texturing involves templated grain growth (TGG) texturing using a BaTiO.sub.3 (BT) template.

A dielectric composition is provided. The dielectric composition includes: a main component made of: a first complex oxide expressed by a chemical formula {K(Ba.sub.1-xSr.sub.x).sub.2Nb.sub.5O.sub.15}; and a second complex oxide expressed by a chemical formula that differs the chemical formula of the first complex oxide. The second complex oxide is a complex oxide expressed by one of chemical formulae: {(Ca.sub.1-ySr.sub.y)(Zr.sub.1-zTi.sub.z)O.sub.3}; {Ba(Ti.sub.1-uZr.sub.u)O.sub.3}; {(Ca.sub.1-vSr.sub.v)TiSiO.sub.5}; and {(Ba.sub.1-wRe.sub.2w/3)Nb.sub.2O.sub.6}, x satisfies 0.35≦x≦0.75, and a satisfies 0.25≦a≦0.75 when a molar ratio between the first and second complex oxides is defined by a:b in an order and a+b=1.00.

A polycrystalline ceramic solid and a method for producing a polycrystalline ceramic solid are disclosed. In an embodiment a polycrystalline ceramic solid includes a main phase with a composition of the general formula: (1-y)Pb.sub.a(Mg.sub.bNb.sub.c)O.sub.3-e+yPb.sub.aTi.sub.dO.sub.3 with 0.055≤y≤0.065, 0.95≤a≤1.02, 0.29≤b≤0.36, 0.63≤c≤0.69, 0.9≤d≤1.1, and 0≤e≤0.1, and optionally one or more secondary phases, wherein, in each section through the solid, a proportion of the secondary phases relative to any given cross-sectional area through the solid is less than or equal to 0.5 percent, or wherein the solid is free of the secondary phases.

A polycrystalline ceramic solid and a method for producing a polycrystalline ceramic solid are disclosed. In an embodiment a polycrystalline ceramic solid includes a main phase with a composition of the general formula: (1-y)Pb.sub.a(Mg.sub.bNb.sub.c)O.sub.3-e+yPb.sub.aTi.sub.dO.sub.3 with 0.055≤y≤0.065, 0.95≤a≤1.02, 0.29≤b≤0.36, 0.63≤c≤0.69, 0.9≤d≤1.1, and 0≤e≤0.1, and optionally one or more secondary phases, wherein, in each section through the solid, a proportion of the secondary phases relative to any given cross-sectional area through the solid is less than or equal to 0.5 percent, or wherein the solid is free of the secondary phases.

The present application provides vanadium dioxide doped with Ti, or vanadium dioxide further doped with other atoms selected from the group of W, Ta, Mo, and Nb. The vanadium dioxide of the present application is excellent in moisture resistance and in which deterioration of endothermic characteristics due to moisture is suppressed.

The present application provides vanadium dioxide doped with Ti, or vanadium dioxide further doped with other atoms selected from the group of W, Ta, Mo, and Nb. The vanadium dioxide of the present application is excellent in moisture resistance and in which deterioration of endothermic characteristics due to moisture is suppressed.

A transparent optical element may include a layer of an electroactive ceramic disposed between transparent electrodes, such that the electrodes are each oriented perpendicular to a non-polar direction of the ceramic layer. Optical properties of the optical element, including transmissivity, haze, and clarity may be improved by the application of a voltage to the electroactive ceramic, and an associated phase transformation.