Structural characteristics, sinterability and electrical conductivity of Ba-site non-stoichiometric BaxCe0.50Zr0.40Y0.10O3−δ

The influence of barium content on the structural characteristics, sinterability and electrical conductivity of proton conductor BaxCe0.50Zr0.40Y0.10O3−δ (x = 0.95, 0.97, 1.00, 1.03, 1.05) is investigated. Compositions with barium deficiency show the presence of fluorite precipitate detected by powder X-ray diffraction, whilst pure perovskite phase is present for other samples. Barium deficiency promotes the densification process of the samples. The electrical conductivity of BaxCe0.50Zr0.40Y0.10O3−δ increases with barium content, which is mainly ascribed to the decreased activation energy due to the increasing lattice volume, especially for the case in wet 5% H2/Ar. The present results suggest that it is very important to control the stoichiometry of cations to obtain desirable perovskite type high temperature proton conductors.