Asahi Glass Company, Limited

Tokyo Institute of Technology

Japan Science and Technology Agency

Satoru Narushima

Hideo Hosono

Masahiro Hirano

Setsuro Ito

Katsuro Hayashi

Sung Wng Kim

Masashi Miyakawa

Sungwng Kim

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.

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.

Growing community of inventors

Tokyo, Japan

Satoru Narushima