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

Pure perovskite structured proton conductive BaCe0.95-xInxTi0.05O3-delta (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)O-3 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%N-2 + 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 degrees C after 80-100 h treatment, which is comparable to the widely-recognized BaCe0.4Zr0.4Y0.2O3-delta 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-delta and BaCe0.4Zr0.4Y0.2O3-delta on the basis of electrochemical impedance spectroscopy analysis further demonstrated that the Ba(Ce,Ti)O-3 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. (C) 2012 Elsevier B. V. All rights reserved.