Abstract: A solid oxide fuel cell (SOFC) contains a first solid electrolyte layer of LaGa-based perovskite, an air electrode, a fuel electrode and a second solid electrolyte layer (having a hole transport number smaller than that of the first solid electrolyte layer), which is provided between the first solid electrolyte layer and an air electrode. Also, another SOFC contains a first solid electrolyte layer of LaGa-based perovskite, an air electrode, a fuel electrode and a third solid electrolyte layer (having electron and proton conductivity lower than that of the first solid electrolyte layer), which is provided between the first solid electrolyte layer and the fuel electrode. Still another SOFC contains the second solid electrolyte layer provided between a first solid electrolyte layer and an air electrode and the third solid electrolyte layer provided between the first solid electrolyte layer and a fuel electrode.

Abstract: A positive electrode active material for a nonaqueous electrolyte secondary battery includes at least a lithium-deficient manganese layered composite oxide represented by the general formula Li1−xMnO2−&dgr;. A lithium deficiency quantity x is in the range of 0.03<x≦0.5. An oxygen nonstoichiometry quantity &dgr; is equal to or smaller than 0.2.

Abstract: A positive electrode active material for a nonaqueous electrolyte secondary battery includes at least a lithium-containing manganese layered composite oxide represented by the general formula Li1−xMO2−y−&dgr;Fy. The second metallic element or constituent M may be Mn or a combination of Mn and substitute metal such as Co, Ni, Cr, Fe, Al, Ga or In. A lithium deficiency quantity x is in the range of 0<x<1. An oxygen defect quantity &dgr; may be equal to or smaller than 0.2. A quantity y of fluorine substituting for part of oxygen is greater than zero.

Abstract: A positive electrode active material for a nonaqueous electrolyte secondary battery includes at least a lithium-containing manganese layered composite oxide represented by the general formula Li1-xMn1-yMyO2-&dgr;. The lithium-containing manganese composite oxide is deficient in lithium with respect to the stoichiometric composition of a layered crystal structure represented by the general formula LiMeO2. Part of Mn is replaced by a substitute metal such as Co, Ni, Fe, Al, Ga, In, V, Nb, Ta, Ti, Zr, Ce or Cr.

Abstract: An electrode material is disclosed which includes: a composite oxide of an A-site defect perovskite structure represented by the following general formula(A'.sub.1-x A".sub.x).sub.1-y (B'.sub.1-y B".sub.y)O.sub.3-.delta.wherein A' is at least one element selected from the group consisting of La, Nd and Y, and A" is at least one element selected from the group consisting of Ba, Sr and Ca, and B' is Co and B" is at least one element selected from the group consisting of Mn, Fe, Ni and Cu, and 0.1.ltoreq..alpha.<0.2, 0<.delta..ltoreq.1, 0<x<1 and 0<y<1; and 2-20 parts by weight of a fluorite oxide based on 100 parts by weight of the composite oxide.

Abstract: A novel composite oxide has an A-site defect type perovskite structure represented by a general formula:A.sub.1--.alpha. BO.sub.3--.delta.wherein A is at least one element selected from the group consisting of alkali metals, alkaline earth metals, rare earth elements, Y and Pb, and B is at least one element selected from the group consisting of Ti, Mn, Fe, Co, Ni, Cu and Al, and .alpha. is 0<.alpha.<0.2 and .delta. is 0.ltoreq..delta..ltoreq.1, provided that only a known perovskite type oxide (La.sub.1-x Sr.sub.x).sub.1-.alpha. MnO.sub.3-.delta. (when .alpha. is 0.06, x is 0.08.ltoreq.x.ltoreq.0.30, while when the value of x is 0.11, .alpha. is 0.06<.alpha.<0.11) is excluded.

Abstract: An n-type thermoelectric material composed mainly of an iron-silicite compound represented by a chemical formula of FeSi.sub.2+z in which -0.1<z<0.1. The thermoelectric material further comprising Co as an n-type dopant and Ge as an additive. The iron-silicon compound is composed substantially of a low temperature phase (.beta.-phase).

Abstract: A method of producing a compound oxide of elements including at least one of thallium, bismuth, lead, antimony, yttrium, each of rare earth elements, each of transition metal elements, each of alkali metal elements and each of alkaline earth metal elements. The method is comprised of the steps of (i) reacting at least one of carbonate, basic carbonate, hydroxide and co-precipitates of each of the above-mentioned elements with an amount of citric acid that is less than the weight equivalent of citric acid needed to form a completely citrated compound, and (ii) calcining the partly citrated compound. The co-precipitate can be one of a carbonate, a basic carbonate and a hydroxide of each of the above-mentioned elements.

Abstract: A composite oxide synthesized by a citrating process and utilized in functional ceramics materials is prepared by the following process. Co-precipitants or mixtures of at least one component selected from the group consisting of carbonates, basic copper and/or hydroxides of elements which compose a composite oxide are reacted with citric acid in an aqueous solution or in an organic solvent. The elements are selected from at least one element of the group consisting of Y, rare earth elements, transition elements, and alkali metal or alkaline earth metal elements. The citrate compound formed is baked to complete the composite oxide.The composite oxide synthesized by this invention has superconduction at the most temperature of 93.degree. K. with excellent Meissner effect.

Abstract: The invention relates to a gas sensor element which utilizes a change in the electric resistance of a porously fired TiO.sub.2 layer. To improve the speed of response of the gas sensor element, and also to strengthen the adhesion of the fired TiO.sub.2 layer to a ceramic substrate, at least one kind of metal oxide which hardly undergoes solid phase reaction with TiO.sub.2 and serves as a sintering suppressing agent, such as Er.sub.2 O.sub.3, Sm.sub.2 O.sub.3 and/or In.sub.2 O.sub.3, is added to TiO.sub.2 in advance of firing. The speed of response is further enhanced by the addition of at least one kind of noble metal such as Pt and/or Rh to TiO.sub.2 together with the sintering suppressing oxide(s).

Abstract: An air/fuel ratio sensor has an oxygen sensor cell including a primary measuring element in direct contact with a gas such as exhaust gases of an automotive engine, and an oxygen pump cell formed by inner and outer electrodes and a cover of an oxygen ion conductive solid electrolyte which confines the primary measuring element within a gas diffusion control space, and which has a small gas diffusion hole. The primary measuring element is formed with a central opening whose center lies right below the gas diffusion hole, in order to reduce a burden imposed on the oxygen pump cell and prevent overshoot in a sensor response characteristic.