Stability aspects of porous Ba0.5Sr0.5Co0.8Fe0.2O3−δ

Porous substrates are a prerequisite for advanced oxygen transport membranes. In particular, phase stability and mechanical robustness are of concern for long term performance and reliability. These aspects were investigated for porous Ba0.5Sr0.5Co0.8Fe0.2O3−δ material using annealing experiments along with microstructural investigations, depth-sensitive micro-indentation and ring-on-ring bi-axial bending tests. Annealing studies revealed phase instabilities at elevated temperatures that were also characterized by X-ray diffraction analysis. Elastic modulus and fracture stress were strongly affected by the porosity, whereas their temperature dependency agreed with the behavior of dense material.