Abstract: A proton conductor includes a main constituent element. A part of the main constituent element is substituted by a transition metal. Valence of the transition metal is variable between valence of the main constituent element and valence lower than the valence of the main constituent element.

Abstract: An electrochemical cell including a proton conductor as an electrolyte with superior stability, particularly against gases containing carbon dioxide, is provided. A proton-conductive electrolyte 21 used for an electrochemical cell 20B was a ceramic having the composition SrZr0.5Ce0.4Y0.1O3??. As the cathode, a thin film of a proton conductor having the composition SrCe0.95Yb0.05O3??was provided on the electrolyte 21 as an intermediate layer 22, and a porous platinum electrode 23c was provided thereon. The anode used was a palladium electrode 23a. A cell 20A including no intermediate layer 22 had a high overvoltage approaching 600 mV at a low current density, namely, 70 mA/cm2. In contrast, the cell 20B, including the intermediate layer 21, had a low overvoltage, namely, about 170 mV, at a current density of 680 mA/cm2.

Abstract: A proton conductive electrolyte (20) is made of AB(1?x)MxO3 structure perovskite, and is characterized in that: the B is Ce; the M is a metal having valence that is smaller than +4; and an average of an ion radius of the M is less than an ion radius of Tm3+ and more than 56.4 pm.

Abstract: [Problem to be Solved] To provide an electrolyte membrane for electrochemical cells excellent in oxide ion permeability, and a method of producing the same. [Solution] An electrolyte membrane for electrochemical cells that is made of an oxide ion conductor having a component composition expressed by a general formula: La1-XSrXGa1-YMgYO3 (where X=0.05 to 0.3, and Y=0.025 to 0.3), and having a perovskite type crystal structure, wherein the electrolyte membrane has a thickness of 1 to 10 ?m and a columnar crystal structure grown to a membrane surface in a direction perpendicular to a membrane face, and wherein the perovskite type crystal structure of the electrolyte membrane having the columnar crystal structure grown to the membrane surface, has a crystal structure with [112] direction oriented perpendicularly to the membrane face.

Abstract: A fuel electrode precursor of low shrinkage rate in an electric power generation cell for a solid oxide fuel cell is provided, wherein: the fuel electrode precursor is made of a sintered body prepared from a green body constituted with oxide ceramic grains composed of at least one of yttria-stabilized zirconia, scandia-stabilized zirconia, samarium-doped ceria and gadolinium-doped ceria and metal oxide grains composed of at least one of nickel oxide, copper oxide and ruthenium oxide; and the fuel electrode precursor at least has a structure in which an iron-containing oxide is present in a grain boundary surrounding the metal oxide grains.

Abstract: An oxide-ion conductor has the formula Ln1?xAxGa1?y?xB1YB2z oxide, wherein Ln is at least one element selected from the group consisting of La, Ce, Pr, Nd and Sm; A is at least one element selected from the group consisting of Sr, Ca and Ba; B1 is at least one element selected from the group consisting of Mg, Al and In; B2 is at least one element selected from the group consisting of Co, Fe, Ni and Cu; x is 0.05 to 0.3; y is 0 to 0.29; z is 0.01 to 0.3; and y+z is 0.025 to 0.3. The oxide-ion conductor exhibits higher oxide-ion conductivity than stabilized zirconia, excellent heat resistance and also high ion conductivity even at low temperatures, as well as exhibiting low oxygen-partial-pressure dependence of ion conductivity.

Abstract: An oxide-ion conductor has the formula Ln1-xAxGa1-y-xB1yB2z oxide, wherein Ln is at least one element selected from the group consisting of La, Ce, Pr, Nd and Sm; A is at least one element selected from the group consisting of Sr, Ca and Ba; B1 is at least one element selected from the group consisting of Mg, Al and In; B2 is at least one element selected from the group consisting of Co, Fe, Ni and Cu; x is 0.05 to 0.3; y is 0 to 0.29; z is 0.01 to 0.3; and y+z is 0.025 to 0.3. The oxide-ion conductor exhibits higher oxide-ion conductivity than stabilized zirconia, excellent heat resistance and also high ion conductivity even at low temperatures, as well as exhibiting low oxygen-partial-pressure dependence of ion conductivity.

Abstract: An oxide ion mixed conductive substance has the formula of A.sub.1-x Ca.sub.x Ga.sub.1-y B.sub.y oxide, wherein A is at least one lanthanoid element having a trivalent octacoordinated ion radius of 1.05 to 1.15 .ANG., B is at least one element selected from the group consisting of Co, Fe, Ni and Cu, x is 0.05 to 0.3, y is 0.05 to 0.3. The oxide ion mixed conductive substance has the perovskite structure.

Abstract: A method for manufacturing a thin zirconia film comprises the steps: (a) preparing a suspension in which partially-stabilized or stabilized zirconia particles having electric charges are dispersed in a solvent; (b) positioning a pair of electrodes in the suspension; (c) applying an electric field between the electrodes, said zirconia particles moving to the electrode and said zirconia particles being deposited on the electrode electrochemically; and (d) sintering the zirconia film to form a partially-stabilized or stabilized thin zirconia film.

Abstract: Disclosed is a method for producing long silicon nitride whiskers. The production method encompasses reacting diatomaceous earth on a carbon boat in a gas flow composed of a reducing agent and a nitriding agent at a temperature of 1,200.degree.-1,700.degree. C.