High temperature compressive creep behavior of BaCe 0.65 Zr 0.2 Y 0.15 O 3−δ in air and 4% H 2 /Ar

The proton conductive material BaCe 0.65 Zr 0.2 Y 0.15 O 3− δ has great potential for the separation and purification of hydrogen. However, due to the demanding application conditions regarding both temperature and atmosphere, the elevated temperature structural stability needs to be characterized and warranted. Hence, in this research work, the elevated temperature compressive creep behavior of BaCe 0.65 Zr 0.2 Y 0.15 O 3− δ in the temperature regime of 850°C to 1200°C was studied in both air and 4% H 2 /Ar as a function of the applied stress. The results indicate different creep mechanisms depending on atmosphere and temperature range. While dislocation creep was observed in 4% H 2 /Ar over the full range, a dislocation creep mechanism was observed in air at temperatures ≤1050°C and a diffusional creep mechanism at temperature ≥1100°C. A detailed microstructural analysis of the post‐creep test specimens revealed that the exposure to oxygen leads to localized stoichiometric changes and a decomposition at the surface.