TONIC CONDUCTOR OF OXIDE AND SOLID ELECTROLYTE TYPE FUEL CELL

摘要

PROBLEM TO BE SOLVED: To obtain an electrolytic material having excellent electroconductivity in a wide temperature range, comprising a Ba2 In2 O5 -based compound containing a trivalent cation except In. SOLUTION: This compound is shown by the formula Ba2 (In1-x Mx )2 O5 (M is a trivalent cation except In; (x) is 0.05-0.95). The compound has a crystal phase which is substantially a monophase and does not show a transition phase at 500-1,000 deg.C. M is preferably a trivalent cation selected from the group IIIa and group IIIb or a trivalent cation having 0.4-1.2 Å ionic radius in a six- coordination and Ga, Gd or Y is preferably cited as M. The compound is an icnic conductor of oxide having >=-2.5 logarithm of conductivity (S/cm) value at 1,000 deg.C and >=-4.5 logarithm conductivity value at 500 deg.C. The oxygen vacancy in the crystal is disordered, a defect perovskite structure having improved symmetry is maintained to a low temperature and reduction in conductivity is controlled by partially replacing In with another cation.