Barium cerate (BaCeO3) has high proton conductivity but rather poor chemical stability in CO2-containing atmospheres. Barium zirconate (BaZrO3), in contrast, is a rather stable material, but exhibits poor sinterability. In the present work, powders of Y-doped BaCeO3 and BaZrO3 were synthesized via the solid solution reaction method, and dense ceramic membranes with BaCe0.9Y0.1O3 and BaZr0.85Y0.15O3 were prepared by the aerosol deposition method at room temperature. Aerosol deposition method is a technique that enables the fabrication of ceramic films at room temperature with a high deposition rate as well as strong adhesion to the substrate. The powders and aerosol-deposited membranes were characterized by X-ray diffraction, particle size analysis, scanning electron microscopy, and X-ray elemental mapping. The chemical stability of powders and aerosol-deposited membranes with BaCe0.9Y0.1O3 and BaZr0.85Y0.15O3 against water and carbon dioxide has been investigated, and it was found that BaZr0.85Y0.15O3 materials showed a better chemical compatibility. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.