Abstract: A carbon dioxide sensor includes: a solid electrolyte layer that is anion conductive; a reference electrode disposed on one surface of the solid electrolyte layer; and a detection electrode disposed on the other surface of the solid electrolyte layer. The detection electrode is made of a mixture containing: (a) one or more metals selected from the group consisting of Au, Ag, Pt, Pd, Rh, Ru, Os, and Ir; (b) a cation conductive carbonate; and (c) an oxide containing Li and at least one of Ce and Sm. The solid electrolyte layer is preferably oxide ion conductive, and the cation conductive carbonate is preferably lithium ion conductive.

Abstract: A carbon monoxide gas sensor is a single-chamber sensor for measuring the carbon monoxide gas concentration in a gas phase. The carbon monoxide gas sensor has electrodes disposed on respective sides of a solid electrolyte layer. One of the electrodes is active for oxidation of carbon monoxide gas, and the other of the electrodes is more inactive for oxidation of carbon monoxide gas than the one electrode. The carbon monoxide gas sensor is configured to measure a short-circuit current between the electrodes. In the carbon monoxide gas sensor, the solid electrolyte layer has oxide ion conductivity.

Abstract: A production method includes: heating a first stacked body at 1000° C. or more, the first stacked body having: a layer containing an oxide represented by the composition formula: La2Si2O7; a first layer provided on one side of the oxide-containing layer and containing cerium oxide doped with a lanthanum element; and a layer provided on the first layer opposite to the oxide-containing layer and containing nickel oxide, and thereby generating, from the oxide represented by the composition formula, a solid electrolyte that has an apatite structure and is c-axis oriented; placing a second layer containing cerium oxide doped or not doped with an Ln element (a rare earth element other than cerium), on the solid electrolyte-containing layer opposite to the cerium oxide-containing layer, and thereby obtaining a second stacked body; and heating the second stacked body at 1000° C. or more.

Abstract: Provided is a gas concentration measuring device including a heat generating resistor that generates heat when electricity is supplied and a stage supporting the resistor. The resistor and the stage overlap in plan view. The stage has a plan view area S of 3.6×107 ?m2 or less. The ratio of the area S to the total volume V of the heat generating resistor and the stage, S/V, ranges from 0.0010 to 10 ?m?1. The device is configured to measure an oxygen gas concentration in a sample gas on the basis of the resistance of the heat generating resistor.

Abstract: A solid electrolyte assembly includes a substrate, a solid electrolyte, and a first electrode and a second electrode. The solid electrolyte has oxide ion conductivity, and the first electrode is located under the solid electrolyte and contains a porous material. The first electrode has only one oxygen diffusion path that is formed overlapping the substrate and the solid electrolyte. When Sr represents the smallest cross-sectional area that is a cross-sectional area of the oxygen diffusion path at a location where the area of a cross section of the first electrode taken perpendicularly to an oxygen diffusing direction is smallest in a portion of the oxygen diffusion path where the oxygen diffusion path overlaps the substrate and the solid electrolyte in a plan view of the solid electrolyte assembly, and Sp represents the area of a region where the first electrode and the second electrode overlap each other in a plan view of the solid electrolyte, Sr/Sp is from 1×10?7 to 6.9×10?4.

Abstract: A solid electrolyte assembly has an anode, a cathode, and a solid electrolyte layer located therebetween. An intermediate layer is provided between the anode or the cathode and the solid electrolyte layer. The intermediate layer is made of a cerium oxide containing lanthanum and a rare-earth element excluding lanthanum and cerium. The solid electrolyte layer contains an oxide of lanthanum. Preferably, the solid electrolyte layer contains a composite oxide of lanthanum and silicon. Also, preferably, the intermediate layer is made of a cerium oxide containing lanthanum and any one of samarium, gadolinium, yttrium, erbium, ytterbium, and dysprosium.

Abstract: Provided is a gas concentration measuring device including a heat generating resistor that generates heat when electricity is supplied and a stage supporting the resistor. The resistor and the stage overlap in plan view. The stage has a plan view area S of 3.6×107 ?m2 or less. The ratio of the area S to the total volume V of the heat generating resistor and the stage, S/V, ranges from 0.0010 to 10 ?m?1. The device is configured to measure an oxygen gas concentration in a sample gas on the basis of the resistance of the heat generating resistor.

Abstract: A solid electrolyte assembly includes a substrate, a solid electrolyte, and a first electrode and a second electrode. The solid electrolyte has oxide ion conductivity, and the first electrode is located under the solid electrolyte and contains a porous material. The first electrode has only one oxygen diffusion path that is formed overlapping the substrate and the solid electrolyte. When Sr represents the smallest cross-sectional area that is a cross-sectional area of the oxygen diffusion path at a location where the area of a cross section of the first electrode taken perpendicularly to an oxygen diffusing direction is smallest in a portion of the oxygen diffusion path where the oxygen diffusion path overlaps the substrate and the solid electrolyte in a plan view of the solid electrolyte assembly, and Sp represents the area of a region where the first electrode and the second electrode overlap each other in a plan view of the solid electrolyte, Sr/Sp is from 1×10?7 to 6.9×10?4.

Abstract: A carbon monoxide gas sensor is a single-chamber sensor for measuring the carbon monoxide gas concentration in a gas phase. The carbon monoxide gas sensor has electrodes disposed on respective sides of a solid electrolyte layer. One of the electrodes is active for oxidation of carbon monoxide gas, and the other of the electrodes is more inactive for oxidation of carbon monoxide gas than the one electrode. The carbon monoxide gas sensor is configured to measure a short-circuit current between the electrodes. In the carbon monoxide gas sensor, the solid electrolyte layer has oxide ion conductivity.

Abstract: A solid electrolyte assembly includes a substrate, a first electrode layer, and a solid electrolyte layer, wherein the first electrode layer and the solid electrolyte layer are stacked in this order on one face of the substrate. The first electrode layer includes: platinum or the like; and a metal oxide having ion conductivity. The substrate has a plurality of through-holes (hole portions) extending in a direction that intersects a face of the substrate that is opposed to the first electrode layer. The metal oxide preferably has oxide ion conductivity. The metal oxide preferably includes one or more rare earths.

Abstract: A layered body includes: a substrate; and an oxide portion positioned on the substrate. An oxide that constitutes the oxide portion contains at least two or more rare-earth elements: silicon; and oxygen. The oxide that is contained in the oxide portion exhibits a diffraction peak derived from a (004) plane at a position of 2?=51.9°±0.9° in an X-ray diffraction pattern, and has an apatite crystal structure. The ratio of linear expansion coefficient of the oxide that constitutes the oxide portion in an a-axis direction relative to linear expansion coefficient of the substrate is 0.15 or more and 1.45 or less.

Abstract: A layered body includes: a substrate; and an oxide portion positioned on the substrate. An oxide that constitutes the oxide portion contains at least two or more rare-earth elements: silicon; and oxygen. The oxide that is contained in the oxide portion exhibits a diffraction peak derived from a (004) plane at a position of 2?=51.9°±0.9° in an X-ray diffraction pattern, and has an apatite crystal structure. The ratio of linear expansion coefficient of the oxide that constitutes the oxide portion in an a-axis direction relative to linear expansion coefficient of the substrate is 0.15 or more and 1.45 or less.

Abstract: In a solid electrolyte integrated device including a substrate with electrically insulated surfaces, a first lower electrode layer and a second upper electrode layer are electrically connected to each other on a first main surface side, and a first upper electrode layer, the first lower electrode layer, the second upper electrode layer, and a second lower electrode layer transmit ions and/or have ion redox ability, contain a metal or a metal oxide or both of a metal and a metal oxide, and have a permeable portion.

Abstract: A carbon dioxide sensor includes: a solid electrolyte layer that is anion conductive; a reference electrode disposed on one surface of the solid electrolyte layer; and a detection electrode disposed on the other surface of the solid electrolyte layer. The detection electrode is made of a mixture containing: (a) one or more metals selected from the group consisting of Au, Ag, Pt, Pd, Rh, Ru, Os, and Ir; (b) a cation conductive carbonate; and (c) an oxide containing Li and at least one of Ce and Sm. The solid electrolyte layer is preferably oxide ion conductive, and the cation conductive carbonate is preferably lithium ion conductive.

Abstract: An oriented apatite-type oxide ion conductor includes a composite oxide expressed as A9.33+x[T6.00?yMy]O26.0+z, where A represents one or two or more elements selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Be, Mg, Ca, Sr, and Ba, T represents an element including Si or Ge or both, and M represents one or two or more elements selected from the group consisting of B, Ge, Zn, Sn, W, and Mo, and where x is from ?1.00 to 1.00, y is from 0.40 to less than 1.00, and z is from ?3.00 to 2.00.

Abstract: A solid electrolyte assembly is obtained by joining a solid electrolyte layer having oxide ion conductivity and containing lanthanum and a first electrode layer made of an oxide that is represented by ABO3?? and has a cubic perovskite structure to each other, where A represents an alkaline-earth metal element, B represents a transition metal element, and ? represents a fraction that occurs depending on the valences and amounts of A, B, and O. The oxide contains lanthanum at a part of the A site, and an atom ratio of lanthanum to all the elements occupying the A site is 0.01 or greater and 0.80 or less.

Abstract: An oxygen permeable element includes an anode, a cathode, and a solid electrolyte. With a voltage applied between the anode and the cathode, oxygen gas in the cathode side atmosphere is allowed to pass through the solid electrolyte to the anode side. The oxygen permeable element has interlayers located between the solid electrolyte and at least one of the cathode and the anode, at least one interlayer containing an oxide of bismuth. The solid electrolyte contains an oxide of lanthanum.

Abstract: A solid electrolyte assembly has an anode, a cathode, and a solid electrolyte layer located therebetween. An intermediate layer is provided between the anode or the cathode and the solid electrolyte layer. The intermediate layer is made of a cerium oxide containing lanthanum and a rare-earth element excluding lanthanum and cerium. The solid electrolyte layer contains an oxide of lanthanum. Preferably, the solid electrolyte layer contains a composite oxide of lanthanum and silicon. Also, preferably, the intermediate layer is made of a cerium oxide containing lanthanum and any one of samarium, gadolinium, yttrium, erbium, ytterbium, and dysprosium.

Abstract: An oriented apatite-type oxide ion conductor includes a composite oxide expressed as A9.33+x[T6.00?yMy]O26.0+z, where A represents one or two or more elements selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Be, Mg, Ca, Sr, and Ba, T represents an element including Si or Ge or both, and M represents one or two or more elements selected from the group consisting of B, Ge, Zn, Sn, W, and Mo, and where x is from ?1.00 to 1.00, y is from 0.40 to less than 1.00, and z is from ?3.00 to 2.00.

Abstract: Provided is a substrate/oriented apatite-type composite oxide film complex which is suitable as a solid electrolyte for a battery, a sensor, a separation membrane, or the like, and can be produced inexpensively. Proposed is a substrate/oriented apatite-type composite oxide film complex provided with an oriented apatite-type composite oxide film on a substrate, wherein a film thickness of the oriented apatite-type composite oxide film is 10.0 ?m or less, a degree of orientation (Lotgering method) thereof is 0.6 or more, and a material of the substrate at a side on which at least the oriented apatite-type composite oxide film is formed is a metal, an alloy, a ceramic, or a composite material thereof.