Abstract: Provided is a novel solid electrolyte material of high density and high ionic conductivity, and an all-solid-state lithium ion secondary battery that utilizes the solid electrolyte material. The solid electrolyte material has a chemical composition represented by Li7-3xGaxLa3Zr2O12 (0.08?x<0.5), has a relative density of 99% or higher, belongs to space group I-43d, in the cubic system, and has a garnet-type structure. The lithium ion conductivity of the solid electrolyte material is 2.0×10?3 S/cm or higher. The solid electrolyte material has a lattice constant a such that 1.29 nm?a?1.30 nm, and lithium ions occupy the 12a site, the 12b site and two types of 48e site, and gallium occupies the 12a site and the 12b site, in the crystal structure. The all-solid-state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte. The solid electrolyte is made up of the solid electrolyte material of the present invention.

Abstract: There are provided an oxide dielectric having excellent properties and a solid state electronic device (e.g., a capacitor, a semiconductor device, or a small electromechanical system) having such an oxide dielectric. An oxide layer 30 includes an oxide dielectric (possibly including inevitable impurities) including bismuth (Bi) and niobium (Nb) and having a first crystal phase of a pyrochlore-type crystal structure and a second crystal phase of a ?-BiNbO4-type crystal structure. The oxide layer 30 has a controlled content of the first crystal phase and a controlled content of the second crystal phase, in which the first crystal phase has a dielectric constant that decreases with increasing temperature of the oxide layer 30 in a temperature range of 25° C. or more and 120° C. or less, and the second crystal phase has a dielectric constant that increases with increasing temperature of the oxide layer 30 in the temperature range.

Abstract: [Problem] Provided is an oxide dielectric having superior properties, and a solid state electronic device (for example, a high pass filter, a patch antenna, a capacitor, a semiconductor device, or a microelectromechanical system) including the oxide dielectric. [Solution] The oxide layer 30 according to the present invention includes an oxide (possibly including inevitable impurities) consisting essentially of bismuth (Bi) and niobium (Nb) and having a crystal phase of the pyrochlore-type crystal structure, in which the number of atoms of the above niobium (Nb) is 1.3 or more and 1.7 or less when the number of atoms of the above bismuth (Bi) is assumed to be 1.

Abstract: There are provided an oxide dielectric having excellent properties and a solid state electronic device (e.g., a capacitor, a semiconductor device, or a small electromechanical system) having such an oxide dielectric. An oxide layer 30 includes an oxide dielectric (possibly including inevitable impurities) including bismuth (Bi) and niobium (Nb) and having a first crystal phase of a pyrochlore-type crystal structure and a second crystal phase of a ?-BiNbO4-type crystal structure. The oxide layer 30 has a controlled content of the first crystal phase and a controlled content of the second crystal phase, in which the first crystal phase has a dielectric constant that decreases with increasing temperature of the oxide layer 30 in a temperature range of 25° C. or more and 120° C. or less, and the second crystal phase has a dielectric constant that increases with increasing temperature of the oxide layer 30 in the temperature range.