Sintering properties of trivalent cation-doped barium zirconate at 1600°C

Typical microstructures of BaZr0.85 Y0.15 O3-δ sintered for 4-24 h at 1600°C were mixtures of larger and smaller grains. Well-grown and homogeneous grains of BaZr0.85 Y0.15 O3-δ were observed by adding an extra amount of barium oxide from stoichiometric composition or extending the sintering time to 100 h. Such an extra amount of barium oxide is expected to decrease chemical stability in a wet atmosphere, and we observed the precipitation of yttria after 100 h sintering. However, we did not meet such difficulties in sintering BaZr0.85 Sc0.15 O3-δ. Large and uniform grains were observed in BaZr0.85 Sc0.15 O3-δ by sintering for 24 h.