Ceramics that were based upon this material exhibited both protonic and oxide ionic conduction at high temperatures. In order to investigate the relationship between the ionic conduction and the valency of the dopant cation, divalent Ca-doped BaCeO3 was prepared and its conduction was compared with that of trivalent Y-doped materials. It was found that, when the dopant cation was changed from Y to Ca, the protonic and oxide ionic conductivities both decreased. Electrochemical tracer experiments showed that the decrease in protonic conductivity could be attributed to decreases in the proton concentration and mobility.

H.Iwahara, T.Mori, T.Hibino: Solid State Ionics, 1995, 79, 177-82