Reactivity of solid BaCe0.9Y0.1O3-δ towards melted WO3

Abstract High-temperature impregnation of solid single-phase Y-doped BaCeO 3 with melted WO 3 was performed towards the evaluation of the possibility of formation of chemically stable material with relatively high electrical conductivity in this system. Impregnation was performed at 1470 °C as a function of time. Due to the relatively high reactivity in solid BaCe 0.9 Y 0.1 O 3-δ - liquid WO 3 system the reactive and the inner layers were distinguished and analysed. The obtained results clearly indicate the decomposition of Y-doped BaCeO 3 in contacted with melted WO 3 . X-ray diffraction method together with SEM observation, EDS analysis and EIS measurements results were applied to discuss the mechanism of this multi-stage process and the influence of the reaction time on materials structure and microstructure. As it was observed, partial incorporation of tungsten into the barium cerate structure can process not only on the surface of the materials but also in the inner layer of the synthesised materials. This donor-type doping of the perovskite structure finds reflection in both, materials electrical properties and chemical stability towards CO 2 /H 2 O. The decrease of proton defects concentration was observed together with the significant increase of the materials chemical stability in comparison to un-modified single-phase BaCe 0.9 Y 0.1 O 3-δ . The calculated values of activation energy of conductivity confirm the change in the conduction mechanism. Also, the presence of an additional phase in the intergranular voids of doped BaCeO 3 was postulated.