A piezoelectric ceramic composition is represented by a composition formula A.sub.xBO.sub.3 and includes potassium sodium niobate containing K and Na that account for 80% or more of an amount of A-site elements and containing Nb that accounts for 70% or more of an amount of B-site elements. The piezoelectric ceramic composition contains Ta and Fe at a B-site.

There is provided a piezoelectric stack, including: a substrate; an oxide film on the substrate, containing zinc and oxygen as main elements; an electrode film on the oxide film; and a piezoelectric film on the electrode film, being an alkali niobium oxide film containing potassium, sodium, niobium, and oxygen and having a perovskite structure.

In a piezoelectric ceramic composition including potassium sodium niobate, a transition temperature at which a phase transition between an orthorhombic crystal structure and a tetragonal crystal structure occurs lies in a temperature range of −20° C. or higher and 60° C. or lower. In the piezoelectric ceramic composition, αt/αO is 0.72 or more, where αO represents a coefficient of linear expansion determined when a crystal structure is orthorhombic in the temperature range, and αt represents a coefficient of linear expansion determined when a crystal structure is tetragonal in the temperature range.

A precursor solution of a garnet-type solid electrolyte is provided represented by the compositional formula: Li.sub.7−xLa.sub.3(Zr.sub.2−xM.sub.x)O.sub.12, wherein in the compositional formula, the element M is two or more types of elements selected from Nb, Ta, and Sb, and x satisfies 0.0<x<2.0, the precursor solution contains one type of solvent, and a lithium compound, a lanthanum compound, a zirconium compound, and a compound containing the element M, each of which has solubility in the solvent, and with respect to the stoichiometric composition of the compositional formula, the amount of the lithium compound is 1.05 times or more and 1.20 times or less, the amount of the lanthanum compound is equal, the amount of the zirconium compound is equal, and the amount of the compound containing the element M is equal.

The embodiments herein relate to electrochromic stacks, electrochromic devices, and methods and apparatus for making such stacks and devices. In various embodiments, an anodically coloring layer in an electrochromic stack or device is fabricated to include nickel-tungsten-niobium-oxide (NiWNbO). This material is particularly beneficial in that it is very transparent in its clear state.

A piezoelectric composition containing: at least one or more elements selected from alkali metal elements; at least one or more elements selected from a group consisting of vanadium, niobium, and tantalum; copper or copper and germanium; and oxygen. The piezoelectric composition has a main phase, and a high Cu-concentration phase in which a content ratio of copper is higher than the main phase, and when a content ratio of oxygen in the high Cu-concentration phase is set as O.sub.g, and a content ratio of copper is set as Cu.sub.g, O.sub.g and Cu.sub.g satisfy relationships of 51≤O.sub.g≤60 and 2.0≤Cu.sub.g≤15.

The invention relates to active electrode materials and to methods for the manufacture of active electrode materials. Such materials are of interest as active electrode materials in lithium-ion or sodium-ion batteries. The invention provides an active electrode material expressed by the general formula M1.sub.aM2.sub.2-aM3.sub.bNb.sub.34-bO.sub.87-c-dQ.sub.d.

Disclosed are embodiments of tungsten bronze crystal structures that can have both a high dielectric constant and low temperature coefficient, making them advantageous for applications that experience temperature changes and gradients. In particular, tantalum can be substituted into the crystal structure to improve properties. Embodiments of the material can be useful for radiofrequency applications such as resonators and antennas.

A solid state ionic conductive electrolyte membrane may include a garnet-like structure oxide material. A solid state ionic conductive electrolyte membrane may include a multi-channel porous support structure and a solid state ionic conductive electrolyte in the multi-channel porous support structure. Systems and methods for selectively extracting alkaline metals include the solid state ionic conductive electrolyte membrane.

A cathode configured to use oxygen as a cathode active material includes: a porous film including a metal oxide, where a porosity of the porous film is about 50 volume percent to about 95 volume percent, based on a total volume of the porous film, and an amount of an organic component in the porous film is 0 to about 2 weight percent, based on a total weight of the porous film.