A New Candidate for the Solid Oxide Fuel Cell Cathode,  Y 0.9Ca0.1FeO3 : Electrical Transport Properties and Defect Structure

The total electrical conductivity, ionic conductivity, and thermopower have been measured as functions of temperature and oxygen partial pressure on the system of (x = 0.1), a newly proposed solid oxide fuel cell (SOFC) cathode material. The majority ionic carriers are identified as oxygen ions via electrotransport experiments. The ionic conductivity, which is in the range of 10−4 to 10−2 S/cm with an activation energy of 1.6 eV in air, tends to increase with increasing PO2 in oxidizing atmospheres and with decreasing PO2 in reducing atmospheres. The defect structure of system is thus explained on the basis of anti‐Frenkel disorder. Thermodynamic stability of the system is also discussed.