OXIDE IONIC MIXED CONDUCTOR AND USE THEREOF

摘要

PROBLEM TO BE SOLVED: To obtain a conductor capable of manifesting a good electron-oxide ionic conductivity over wide oxygen partial pressures ranging from a reducing atmosphere to an oxidizing atmosphere and within a wide temperature range and having a high electroconductivity and a small temperature change thereof by providing a rare earth gallate-based perovskite type oxide ionic mixed conductor with a composition represented by a specific relationship. SOLUTION: This oxide ionic conductor is represented by the general formula: A1-x Cax Ga1-y By O3 [A is one or more kinds of lanthanoid metals having 1.05-1.15 Åionic radius of trivalent ions in the 8 coordination; B is one or more kinds of Co, Fe Ni and Cu; (x) is 0.05-0.3; (y) is 0.05-0.3]. Since the oxide ionic conductor is capable of manifesting an excellent electron-oxide ionic conductivity and the electronic electrical conduction by positive holes is raised especially in an oxidizing atmosphere, the oxide ionic conductor is useful for an air electrode of a solid oxide type fuel cell. The material is further useful as a gas separation membrane such as an air separation membrane.