Provided is a zirconia sintered body that uses coloring of cerium oxide, the zirconia sintered body exhibiting a bright red color. The zirconia sintered body includes an oxide of cerium is an amount of 0.5% by mole or more and less than 4% by mole in terms of CeO.sub.2, yttria in an amount of 2% by mole or more and less than 6% by mole, an oxide of aluminum in an amount of 0.1% by weight or more and less than 2% by weight, and the balance being zirconia. The oxide of cerium contains trivalent cerium, and the zirconia has a crystal structure including a tetragonal phase.

The present invention relates to a strontium magnesium molybdenum oxide material having perovskite structure and the method for preparing the same. Citric acid is adopted as the chelating agent. By using sol-gel pyrolysis and replacing a portion of strontium in Sr.sub.2MgMoO.sub.6- by cerium and a portion of magnesium by copper, a material with a chemical formula of Sr.sub.2-xCe.sub.xMg.sub.1-yCu.sub.yMoO.sub.6- is produced, where 0x<2, 0<y<1, and 0<<6. Thereby, the electrical conductivity of the material is improved. The perovskite-type cerium- and copper-replaced strontium magnesium molybdenum oxide significantly increases the electrical conductivity of the material and can be applied as the anode material for solid oxide fuel cell (SOFC).

The invention relates to a refractory product comprising zirconium dioxide, a use of zirconium dioxide, a zirconium dioxide, a method for manufacturing a refractory product and a refractory product manufactured by means of said method. The zirconium dioxide is in cubic form and is metastable at room temperature. The zirconium dioxide has a content of calcium, magnesium and yttrium of less than 1% by weight.

A cermet material, including a plurality of ceramic particles defining a ceramic portion; and a plurality of high magnetic permeability metallic particles distributed throughout the ceramic portion to define an admixture. The ceramic particles and the metallic particles are generally the same size and shape. Each respective high magnetic permeability metallic particle has a magnetic permeability of at least 0.0001 H/m. The ceramic particles are selected from the group consisting of zirconia, yttria stabilized zirconia, zirconia toughened alumina, alumina, gadolinium oxide, TiB.sub.2, ZrB.sub.2, HfB.sub.2, TaB.sub.2, TiC, Cr.sub.3C.sub.2, and combinations thereof.

Watch component made of a persistent phosphorescent ceramic composite material which is a sintered dense body comprising two or more phases, a first phase consisting of at least one metal oxide and a second phase consisting of a metal oxide containing at least one activating element in a reduced oxidation state, the watch component having a surface which comprises an area which shows phosphorescent emission and an area which does not show phosphorescent emission or which shows phosphorescent emission with an intensity which is lower than that of the emission of the other area.

A nanoheterostructure includes a first inorganic component and a second inorganic component one of which is a matrix, and the other of which is three-dimensionally and periodically arranged in the matrix, and has a three-dimensional periodic structure whose average value of one unit length of a repeated structure is 1 nm to 100 nm.

Provided are a macroporous titanium compound monolith and a production method thereof, the macroporous titanium compound monolith having a framework that is composed of a titanium compound other than titanium dioxide, having controlled macropores, and having electron conductivity, the titanium compound being oxygen-deficient titanium oxide, titanium oxynitride, or titanium nitride. Provided is a method including: placing a macroporous titanium dioxide monolith and a metal having titanium-reducing ability in a container, the macroporous titanium dioxide monolith having a co-continuous structure of a macropore and a framework that is composed of titanium dioxide; creating a vacuum atmosphere or an inert gas atmosphere within the container; and heating the monolith and the metal to cause gas-phase reduction that removes oxygen atom from the titanium dioxide composing the monolith by the metal acting as an oxygen getter, thereby obtaining a macroporous oxygen-deficient titanium oxide monolith having a co-continuous structure of the macropore and a framework that is composed of oxygen-deficient titanium oxide, the macroporous oxygen-deficient titanium oxide monolith having electron conductivity derived from the oxygen-deficient titanium oxide.

A production method of an electroconductive mayenite compound having an electron density greater than or equal to 510.sup.20 cm.sup.3 includes preparing an object of processing containing a mayenite compound or a precursor of a mayenite compound, placing aluminum foil on at least part of a surface of the object of processing, and retaining the object of processing at temperatures falling within the range of 1080 C. to 1450 C. in a low oxygen partial pressure atmosphere.

A method of manufacturing an electrically conductive mayenite compound, includes preparing a body to be processed including a mayenite compound; and placing the body to be processed in the presence of carbon monoxide gas and aluminum vapor supplied from an aluminum source without being in contact with the aluminum source and retaining the body to be processed at a temperature range of 1080 C. to 1450 C. under a reducing atmosphere.

The present invention relates to a strontium magnesium molybdenum oxide material having perovskite structure and the method for preparing the same. Citric acid is adopted as the chelating agent. By using sol-gel pyrolysis and replacing a portion of strontium in Sr.sub.2MgMoO.sub.6- by cerium and a portion of magnesium by copper, a material with a chemical formula of Sr.sub.2-xCe.sub.xMg.sub.1-yCu.sub.yMoO.sub.6- is produced, where 0x<2, 0<y<1, and 0<<6. Thereby, the electrical conductivity of the material is improved. The perovskite-type cerium- and copper-replaced strontium magnesium molybdenum oxide significantly increases the electrical conductivity of the material and can be applied as the anode material for solid oxide fuel cell (SOFC).