Influence of In doping on the structure, stability and electrical conduction behavior of Ba(Ce,Ti)O3 solid solution

Abstract

Pure perovskite structured proton conductive BaCe0.95−xInxTi0.05O3−δ (x=0.1, 0.2, 0.3, 0.4) powders were prepared by a modified Pechini method. The influences of indium doping on the performance of Ba(Ce,Ti)O3 solid solution, especially on the chemical stability and electrical conductivity were systematically investigated. With the increase of indium concentration, the chemical stability against the atmosphere containing CO2 and H2O (94%N2+3%CO2+3%H2O) was gradually enhanced. At the In doping level of 0.3 and 0.4, almost no any phase change is found in the powders at 700°C after 80–100h treatment, which is comparable to the widely-recognized BaCe0.4Zr0.4Y0.2O3−δ proton conductor. The specimen with the In content of 0.3 displayed the highest conductivity under all the atmospheres studied. Comparison between BaCe0.65In0.3Ti0.05O3−δ and BaCe0.4Zr0.4Y0.2O3−δ on the basis of electrochemical impedance spectroscopy analysis further demonstrated that the Ba(Ce,Ti)O3 solid solution containing proper indium content is more conductive and also a potential proton conductor to be used as electrolytes for solid oxide fuel cells.