A piezoelectric PTZT film is formed of a metal oxide having a perovskite structure including Pb, Ta, Zr, and Ti, in which the metal oxide further includes carbon, and a content of the carbon is 80 to 800 ppm by mass. In a process for producing a liquid composition for forming a piezoelectric film, a Ta alkoxide, a Zr alkoxide, -diketones, and a diol are refluxed, a Ti alkoxide is added into a first synthesis solution obtained by the refluxing, and then refluxing is performed again, a Pb compound is added into a second synthesis solution obtained by performing the additional refluxing, and then refluxing is performed again, a solvent is removed from a third synthesis solution obtained by performing the additional refluxing, and then, dilution with alcohol is performed, to produce the liquid composition for forming a piezoelectric PTZT film.

To provide a lithium ion conductive crystal body having a high density and a large length and an all-solid state lithium ion secondary battery containing the lithium ion conductive crystal body. A Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body, which is one example of the lithium ion conductive crystal body, has a relative density of 99% or more, belongs to a cubic system, has a garnet-related type structure, and has a length of 2 cm or more. The Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body is grown by a melting method employing a Li.sub.5La.sub.3Ta.sub.2O.sub.12 polycrystal body as a raw material. With the growing method, a Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body having a relative density of 100% can also be obtained. In addition, the all-solid state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, in which the solid electrolyte contains the lithium ion conductive crystal body.

Provided is a dielectric composition which includes, as a main component, a complex oxide represented by a general formula A.sub.aB.sub.bC.sub.4O.sub.15+ and having a tungsten bronze structure, wherein A includes at least Ba, B includes at least Zr, C includes at least Nb, a is 3.05 or higher, and b is 1.01 or higher. In the dielectric composition, when the total number of atoms occupying M2 sites in the tungsten bronze structure is set to 1, the proportion of B is 0.250 or higher. In addition, in the dielectric composition, an X-ray diffraction peak of a (410) plane of the tungsten bronze structure is splitted into two, and an integrated intensity ratio of an integrated intensity of a high-angle side peak of the X-ray diffraction peak with respect to an integrated intensity of a low-angle side peak of the X-ray diffraction peak is 0.125 or higher.

The present disclosure provides a method for preparing a dielectric which can provide a low-dielectric loss dielectric not variable to frequency, wherein the dielectric shows a narrow variation in dielectric characteristics depending on temperature, undergoes no change in dielectric characteristics depending on frequency and thus has a low dielectric loss. The present disclosure also provides a dielectric prepared by the method.

A solid electrolyte capable of securing grain boundary resistance even when firing is performed at a relatively low temperature and a battery using the solid electrolyte are provided. The solid electrolyte includes a first electrolyte which contains a lithium composite metal compound, and a second electrolyte which contains Li and at least two kinds of metal elements selected from group 5 elements in period 5 or higher or group 15 elements in period 5 or higher.

According to one embodiment, provided is an active material including monoclinic niobium titanium composite oxide particles, and carbon fibers with which at least a part of surfaces of the monoclinic niobium titanium composite oxide particles is covered. The monoclinic niobium titanium composite oxide particles satisfy 1.5(/)2.5. The monoclinic niobium titanium composite oxide particles have an average primary particle size of 0.05 m to 2 m. The carbon fibers contain one or more metal elements selected from the group consisting of Fe, Co and Ni, and satisfy 1/10000(/)1/100. The carbon fibers have an average fiber diameter in the range of 5 nm to 100 nm.

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 solid electrolyte material having high ion conductivity and a all-solid-state lithium-ion secondary battery using this solid electrolyte material are provided. The solid electrolyte material has a garnet-related structure crystal represented by the chemical composition Li.sub.7xyLa.sub.3Zr.sub.2xyTa.sub.xNb.sub.yO.sub.12 (0.05x+y0.2, x0, y0), which belongs to an orthorhombic system and a space group belonging to Ibca. The solid electrolyte material has lithium-ion conductivity at 25 C. of at least 1.010.sup.4 S/cm. Also, in this solid electrolyte material, the lattice constants are 1.29 nma1.32 nm, 1.26 nmb1.29 nm, and 1.29 nmc1.32 nm, and three 16f sites and one 8d site in the crystal structure are occupied by lithium-ions. The all-solid-state lithium-ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, the solid electrolyte comprising this solid electrolyte material.

A solid electrolyte material having high ion conductivity and a all-solid-state lithium-ion secondary battery using this solid electrolyte material are provided. The solid electrolyte material has a garnet-related structure crystal represented by the chemical composition Li.sub.7xyLa.sub.3Zr.sub.2xyTa.sub.xNb.sub.yO.sub.12 (0.05x+y0.2, x0, y0), which belongs to an orthorhombic system and a space group belonging to Ibca. The solid electrolyte material has lithium-ion conductivity at 25 C. of at least 1.010.sup.4 S/cm. Also, in this solid electrolyte material, the lattice constants are 1.29 nma1.32 nm, 1.26 nmb1.29 nm, and 1.29 nmc1.32 nm, and three 16f sites and one 8d site in the crystal structure are occupied by lithium-ions. The all-solid-state lithium-ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, the solid electrolyte comprising this solid electrolyte material.

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.