Abstract: A solid oxide fuel cell including at least one kind of an electrically conductive film formed by spraying and having a permeability constant of nitrogen gas being not more than 9.times.10.sup.-8 cm.sup.4 /g.sec. A process for producing a solid oxide fuel cell, including the steps of: forming a sprayed film on a substrate by spraying a material for the formation of an electrically conductive film, while a thickness of a sprayed film per one pass of a spraying gun is being suppressed to not more than 10 .mu.m, and then forming the electrically conductive film by thermally treating the sprayed film.

Abstract: An air electrode body for a solid oxide fuel cell, which is composed of a perovskite-type structure having a chemical composition of (La.sub.1-x A.sub.x).sub.1-y MnO.sub.3 wherein 0<x.ltoreq.0.5, 0<y.ltoreq.0.2, and A is at least one metal selected from strontium, calcium, manganese, barium, yttrium, cerium and ytterbium. The air electrode body has a porosity of 15 to 40% and an average pore diameter of 1-5 .mu.m. A process for producing the air electrode body, includes the steps of: mixing lanthanum or a lanthanum compound, manganese or a manganese compound, a metal A or a compound of the metal A wherein A is at least one kind of metals selected from the group of strontium, calcium, manganese, barium, yttrium, cerium and ytterbium; calcining the resulting mixture at a temperature from 1,300.degree. C. to 1600.degree. C. to synthesize (La.sub.1-x A.sub.x).sub.1-y MnO.sub.3 ; grinding the synthesized material to a powder having an average particle diameter of 3 to 15 .mu.

Abstract: A method for operating a power generator in which a solid oxide fuel cell is used as a power-generating element and an air electrode of the solid oxide fuel cell is composed of lanthanum manganite, the method involving the step of setting a heating rate and a cooling rate at least in a temperature range of 800.degree. C. to 900.degree. C. at not less than 3.degree. C./min. when the fuel cell is heated up to an operating temperature at the time of starting the power generator and when the fuel cell is cooled from the operating temperature at the time of stopping the power generator. Alternatively, the method involves the step of setting a partial pressure of oxygen, at least in a temperature range of 800.degree. C. to 900.degree. C., in an atmosphere to which the air electrode is exposed, to at not less than 10.sup.-15 arms but not more than 10.sup.

Abstract: A porous sintered body composed mainly of lanthanum manganite in which a part of lanthanum atoms at A-sites of the lanthanum manganite are substituted by atoms of a metal selected from the group consisting of alkaline earth metals and rare earth metals. The dimensional shrinkage amount of the porous sintered body in heat cycling between room temperature and 1,000.degree. C. is not more than 0.01% per one heat cycle.

Abstract: An electrically conductive ceramic film having a large size and surface area, a complicated configuration and a high electrical conductivity can be provided by the present melt spray method. The method includes melt spraying a raw material of an electrically conductive ceramic on a substrate to form a melt sprayed film, and heat treating the melt spray film to produce the electrically conductive ceramic film.

Abstract: A method for producing interconnectors for electrically connecting unit cells of a solid electrolyte type fuel cell. An interconnector material such as a perovskite complexed oxide is thermally sprayed onto the surface of an electrode of a solid electrolyte type fuel cell by plasma thermal spraying process at a temperature of not lower than 1,250.degree. C. to form an interconnector, and heat treated to diminish the cracks and defects resulting from the plasma thermal spraying process.

Abstract: A first method for manufacturing a solid oxide film having a highly densified solid oxide film having a small thickness and an improved electric conductivity; and a second method for manufacturing a solid oxide fuel cell in which a solid oxide film formed on an air electrode or a fuel electrode is manufactured by the first method. The solid oxide fuel cell according to the present invention is capable of generating a high power. The solid oxide film is formed on a substrate in such manner that a solid oxide material is sprayed on the substrate to form a sprayed solid oxide film thereon; Then a solution of metal compound including at least one metal selected from a group of manganese, iron, cobalt, nickel, copper and zinc is impregnated into the sprayed solid oxide film; and the sprayed solid oxide film is subjected to a heat treatment in order to increase an airtightness of the film. It may be possible to use a material for spraying, in which 1.about.

Abstract: A solid electrolyte type fuel cell having decreased internal resistance and increased output and improved fuel utilization efficiency is provided. The fuel cell includes an air electrode substrate made of a perovskite series complexed oxide having the following composition of a formula (La.sub.1-y A.sub.y)MO.sub.3, wherein A is at least one element selected from alkaline earth metals, M is manganese or cobalt, and y is 0.ltoreq.y.ltoreq.0.4, a zirconia solid electrolyte film containing manganese or cobalt solid soluted at at least the neighborhood of the interface thereof with the air electrode substrate, and a fuel electrode film formed on the solid electrolyte film at a surface opposite to the air electrode substrate. The fuel cell does not include a highly resistive layer made of a compound containing lanthanum and zirconium at the interface between the air electrode substrate and the solid electrolyte film. Methods for producing the fuel cell are also disclosed.

Abstract: A process for the production of a lanthanum chromite film, including the steps of preparing a plasma spray powder by mixing 1-15 parts by weight of powdery chromium oxide powder to 100 parts by weight of powdery lanthanum chromite, this lanthanum chromite having a composition ratio of A sites to B-sites being in a range of 1:1 to 1:0.9, forming a plasma sprayed film by plasma spraying the plasma spray powder onto a substrate, and forming the lanthanum chromite film by heat treating the resulting plasma sprayed film. The plasma spray powder may be produced by preparing a mixed powder by adding 1-15 parts by weight of powdery chromium oxide to 100 parts by weight of a synthesis powder capable of producing the lanthanum chromite film by heat treatment, the synthesis powder containing at least chromium oxide and lanthanum chromite and the lanthanum chromite film having a composition ratio of A-sites to B-sites being in a range of 1:1 to 1:0.

Abstract: A cell unit for use in a solid oxide fuel cell has a laminate structure including a cell element and a separator. The cell element includes a dense and planar solid electrolyte having a rectangular plane shape, and an air electrode film and a fuel electrode film provided on opposite surfaces of the flat solid electrolyte, respectively. The separator is made of a dense electron conductor. A plurality of oxidizing gas flow paths are defined between the separator and the air electrode, and the cell element has a rectangular planar shape and a ratio of a short side to a long side of the rectangular planar shape is not less than 2.

Abstract: A gradient magnetic field irradiation method comprising irradiating RF pulses and a slice plane selection gradient magnetic field to excite an atomic nucleus of a slice plane, irradiating then first, second and third frequency encoding gradient magnetic fields under the following condition and receiving NMR signals during the irradiation of the third frequency encoding gradient magnetic field:(A) (1/k)-(4/n)+1=0where a ratio of intensity of the first, second and third frequency encoding gradient magnetic field is k:n:1;(B) the irradiation time of the first and second frequency encoding gradient magnetic fields is T/k and 2T/n, respectively, when the irradiation time of the third frequency gradient magnetic field is 2T; and(C) a time interval between the start timing of the irradiation of the first frequency encoding gradient magnetic field and the start timing of the irradiation of the second frequency encoding gradient magnetic field is equal to a time interval between the start timing of the irradiation of

Abstract: A process for producing high density SiC sintered bodies by primarily firing and then hot isostatic pressing. The process includes the steps of formulating a powder consisting essentially of 90.0 to 99.8% by weight of the SiC powder, boron or a boron-containing compound in an amount of 0.1 to 5.0% by weight when calculated as boron, and carbon or a carbon-producing organic compound in an amount of 0.1 to 5.0% by weight when calculated as carbon, mixing and shaping the formulated powder, firing the shaped bodies in a temperature range from 1,900.degree. to 2,300.degree. C. in vacuum or in an inert gas atmosphere, and then hot isostatically pressing the fired bodies in a temperature range from 1,800.degree. to 2,200.degree. C. under a pressure of not less than 100 atms in an inert gas atmosphere. The SiC powder is an SiC mixed powder consisting essentially of 95.0 to 99.

Abstract: A high density SiC sintered body can be obtained by molding a mixture of two kinds of high temperature-type and low temperature-type silicon carbides together with sintering aids into a shaped article, primarily firing the shaped article, and subjecting the primarily sintered body to an HIP treatment.

Abstract: A silicon carbide complex sintered body including 20 to 99 wt % of SiC, 80 to 0.5 wt % of at least one compound selected from the group consisting of W.sub.2 B.sub.5 and/or MoB.sub.2, and 0.5 to 5 wt % of at least one material selected from the group consisting of boron, carbon, and boron carbide. A process for producing the sintered body by preparing a mixed powder is also disclosed, wherein the mixed powder includes 20 to 99 wt % of SiC powder having an average particle diameter of not greater than 5 microns, 80 to 0.5 wt % of at least one compound selected from the group consisting of W.sub.2 B.sub.5 and MoB.sub.2, and 0.1 to 5 wt %, when calculated as boron, of boron or a compound containing boron, and 0.1 to 5 wt %, when calculated as carbon, molding the mixture, and firing the molding in a temperature range from 1,900.degree. to 2,500.degree. C. in vacuum or in an inert atmosphere.

Abstract: In case of manufacturing a voltage non-linear resistor, a sintering process is divided into two completely separate steps, i.e. primary and secondary sinterings. The primary sintering is carried out under a reduced pressure and the second sintering is conducted under an atmospheric pressure with a sufficient amount of oxygen. The primary sintering is effects such that the relative density and open porosity of the primarily sintered body are 85% or more and 1% or less, respectively. The secondary sintering removes to a large extent, voids existing in the body and, oxidation of the body is sufficiently effected. Therefore, the finally sintered body has a high density, a large surge withstanding capability, and a high non-linearity index.

Abstract: A silicon carbide sintered body containing given amounts of Mg, B and free carbon and having a density of not less than 2.80 g/cm.sup.3 is produced by adding given amounts of magnesium boride and carbon to silicon carbide powder having an average grain size of not more than 5 .mu.m, shaping and firing at 1,900.degree..about.2,300.degree. C. under vacuum or in an inert gas atmosphere.