Japan Science and Technology Agency

Asahi Glass Company, Limited

Tokyo Institute of Technology

Agc Inc.

Japan Science and Technology Corporation

Oxy Japan Company Limited

Katsuro Hayashi

Hideo Hosono

Masahiro Hirano

Setsuro Ito

Satoru Narushima

Satoru Watanabe

Kazuhiro Ito

Masashi Miyakawa

Naomichi Miyakawa

Yoshitake Toda

Toshinari Watanabe

Sung Wng Kim

Isao Tanaka

Sungwng Kim

Masayoshi Sadakata

Disclosed herein is an amorphous C12A7 electride thin film which has an electron density of greater than or equal to 2.0×10cmand less than or equal to 2.3×10cm, and exhibits a light absorption at a photon energy position of 4.6 eV. Also disclosed herein is an amorphous thin film which is fabricated using a target made of a crystalline C12A7 electride, and containing an electride of an amorphous solid material including calcium, aluminum, and oxygen, in which an Al/Ca molar ratio of the thin film is 0.5 to 4.7.

Metal oxide thin film, organic electroluminescence element including the thin film, solar cell, and thin film fabrication method

A C12A7 electride thin film fabrication method includes a step of forming an amorphous C12A7 electride thin film on a substrate by vapor deposition under an atmosphere with an oxygen partial pressure of less than 0.1 Pa using a target made of a crystalline C12A7 electride having an electron density within a range of 2.0&#xd7;10cmto 2.3&#xd7;10cm.

C12A7 electride thin film fabrication method and C12A7 electride thin film

Provided is a method for preparing an electroconductive mayenite type compound with good properties readily and stably at low cost. A production method of an electroconductive mayenite type compound comprising a step of subjecting a precursor to heat treatment, is a method for preparing an electroconductive mayenite type compound, comprising a step of subjecting a precursor to heat treatment; wherein the precursor is a vitreous or crystalline material, which contains Ca and Al, in which a molar ratio of (CaO:AlO) is from (12.6:6.4) to (11.7:7.3) as calculated as oxides, and in which a total amount of CaO and AlOis at least 50 mol %, and wherein the heat treatment is heat treatment comprising holding the precursor at a heat treatment temperature T of from 600 to 1415&#xb0; C. and in an inert gas or vacuum atmosphere with an oxygen partial pressure Pin a range of P&#x2266;10&#xd7;exp [{&#x2212;7.9&#xd7;l0/(T+273)}+14.4] in the unit of Pa.

Method for preparing electroconductive mayenite type compound

Provided is a method for preparing an electroconductive mayenite type compound with good properties readily and stably at low cost without need for expensive facilities, a reaction at high temperature and for a long period of time, or complicated control of reaction. A method for preparing an electroconductive mayenite type compound comprises a step of subjecting a precursor to heat treatment, wherein the precursor contains Ca and/or Sr, and Al, a molar ratio of (a total of CaO and SrO:AlO) is from (12.6:6.4) to (11.7:7.3) as calculated as oxides, a total content of CaO, SrO and AlOin the precursor is at least 50 mol %, and the precursor is a vitreous or crystalline material; and the method comprises a step of mixing the precursor with a reducing agent and performing the heat treatment of holding the mixture at 600-1,415&#xb0; C. in an inert gas or vacuum atmosphere with an oxygen partial pressure of at most 10 Pa.

Disclosed is a 12CaO.7AlOcompound, a 12SrO.7AlOcompound, or a mixed crystal compound of 12CaO.7AlOand 12SrO.7AlO, which contains a negative hydrogen ion (H, H, Hat a concentration of 1&#xd7;10cmor more. A negative hydrogen ion comprising a primary component of a hydride ion is incorporated into C12A7 (12CaO.7AlO), so that a function of being converted from an insulative material to an electrically conductive material in a sustained manner by means of irradiation with light can be exhibited even in the normal atmosphere at a room temperature. The present invention also provides a solid electrolyte capable of conducting a negative hydrogen ion, and means for releasing a hydride ion from the inside of a solid into a gaseous phase using an electric field.

Hydrogen-containing electrically conductive inorganic compound

In a solid solution system of AlOand CAO or SrO, it has been difficult to obtain a material having a high electrical conductivity (&#x3e;10S&#xb7;cm) at room temperature. A compound is provided in which electrons at a high concentration are introduced into a 12CaO.7AlOcompound, a 12SrO.7AlOcompound, or a mixed crystal compound containing 12CaO.7AlOand 12SrO.7AlO. The compound formed by substituting all the free oxygen ions with electrons is regarded as an electride compound in which [CaAlO](4e) or [SrAlO](4e) serves as a cation and electrons serve as anions. When a single crystal or a hydrostatic pressure press molded material of a fine powder thereof is held at approximately 700&#xb0; C. in an alkaline metal vapor or an alkaline earth metal vapor, melt of a hydrostatic pressure press molded material of a powder is held at approximately 1,600&#xb0; C. in a carbon crucible, followed by slow cooling for solidification, or a thin film of the compound held at approximately 600&#xb0; C. is implanted with rare gas ions, a great number of the free oxygen ions can be substituted with electrons.

Electroconductive 12CaO&#x2014;7Al2O3 and compound of same type, and method for preparation thereof

To provide a method for preparing a mayenite type compound having electroconductivity imparted. A method for preparing an electroconductive mayenite type compound, which comprises melting a raw material containing Al and at least one element selected from the group consisting of Ca and Sr, holding the melt in a low oxygen partial pressure atmosphere having an oxygen partial pressure of not higher than 10 Pa, followed by cooling or annealing in a low oxygen partial pressure atmosphere or in atmospheric air for solidification, thereby to replace oxygen present in cages by electrons in a high concentration.

The present invention provides a method for producing negatively charged oxygen atoms comprising: placing a negative electrode () on a surface of a member () made of calcium-aluminum composite oxide, proximately placing a positive electrode () on a side of the member opposite to the surface on which the negative electrode is placed, supplying oxygen to the negative electrode side, and applying voltage between the negative electrode and the positive electrode so as to extract negatively charged oxygen atoms (A) from the side where the positive electrode () is placed. The present invention also provides an apparatus for producing negatively charged oxygen atoms which is used for the above method.

Negatively-charged oxygen atom producing method and producing apparatus

There is provided a C12A7 compound capable of selectively and reversibly clathrating Xions, such as active oxygen radicals, with improved controllability. The C12A7 compound clathrating OHions and Onat a concentration of 2&#xd7;10cmor less can be prepared by subjecting a mixed material containing Ca and Al to a solid phase reaction at a firing temperature not lower than 1200&#xb0; C. and lower than 1449&#xb0; C. in a dry oxygen atmosphere having an oxygen partial pressure of 0.1 atm or more and a water vapor partial pressure of 10atm or less, keeping the resultant product at a temperature of 1200&#xb0; C. or higher, and cooling rapidly. The C12A7 compound is heat-treated to clathrate OHions at a concentration of 2&#xd7;10cmor less, and Onat a high concentration of more than 2&#xd7;10cm. The compound can reversibly clathrate or release Onion radicals through the elevation or lowering of the temperature thereof in a temperature range of 300 to 850&#xb0; C. The compound is useful for an oxidation catalyst, an anti-bacterial agent, an ion conducting material, an electrode for a solid-electrolyte fuel cell, and the like.

[object Object]

The present invention provides a 12CaO.7Al O compound containing an O ion radical and/or an O ion radical in a high concentration of 10 cm or more. This compound can be used as an oxidization catalyst, antibacterial agent, ion conductor, or electrode material for solid-oxide fuel cells.

Growing community of inventors

Kawasaki, Japan

Katsuro Hayashi