Studies on Chemical Stability and Electrical Properties of Proton Conducting Perovskite-Like Doped BaCeO[sub 3]

The chemical stability and electrical properties of three promising perovskite-related structures , , and were tested in air, humidified and , as well as in . Powder X-ray diffraction studies confirmed the formation of a cubic perovskite-like structure. The change in the lattice constant was consistent with B-site substitution in . All the investigated compounds formed barium carbonate in at elevated temperatures and were found to be chemically unstable in boiling . The data showed that these three compounds are chemically stable in humidified at ; however, at , the formation of barium carbonate was observed. The electrical conductivity in wet and/or was found to be higher than that in the -containing atmosphere, confirming proton conduction in the doped . The co-doped showed the highest total conductivity of in at with an activation energy of 0.36 eV in the temperature range of .