Influence of Ba non-stoichiometry on the processing properties of Y- and Sc-doped BaZrO3
Julian N. Ebert, Dylan Jennings, Walter Sebastian Scheld, Doris Sebold, Wolfgang Rheinheimer
Abstract
Y-doped BaZrO3 is a well-researched material for proton-conducting fuel cells. One of the main limitations is the very high sintering temperature (~ 1600 °C) necessary to densify the material. As Ba is lost at this temperature due to BaO evaporation, the stoichiometry is changed uncontrollably. This study is focused on evaluating the influence of slight changes in stoichiometry on microstructure, chemical stability, and conductivity of 20% Y-doped BaZrO3 (BZY20) as well as 10% Y- and 10% Sc-co-doped BaZrO3 (BZY10Sc10). Overall, Ba excess resulted denser microstructures with larger grains. Still, these samples were prone to decomposition by forming BaCO3. Therefore, a slight Ba deficiency is favorable as the conductivity did not suffer in the examined stoichiometry region.