Synthesis, structure and electrical conductivity of a new perovskite type barium cobaltate BaCoO1.80(OH)0.86

Perovskite oxides exhibiting mixed protonic and electronic conductivities have interesting applications in protonic ceramic fuel cells. In this work, we report on a hydrated phase of BaCoO1.80(OH)0.86 synthesized using nebulized spray pyrolysis. Structural analysis based on X-ray and neutron powder diffraction data showed that the compound is isotypic to BaFeO2.33(OH)0.33. The water loss behaviour was studied using simultaneous thermal analysis and high temperature X-ray diffraction, indicating that protons (respectively water) can be stabilized within the compound up to temperatures significantly above 673 K, confirmed by ex-situ Fourier transform infrared spectroscopy studies. Impedance spectroscopy was used to determine the conductivity characteristics of BaCoO1.80(OH)0.86, finding a total electrical conductivity in the order of 10 4 S cm-1 at ambient temperature with an activation energy of 0.28 eV.