Influence of Ce0.9Gd0.1O2 − δ particles on microstructure and oxygen permeability of Ba0.5Sr0.5Co0.8Fe0.2O3 − δ composite membrane

This study examined the oxygen permeation behavior of Ce0.9Gd0.1O2 − δ (Gadolinium-Doped Ceria, GDC)/Ba0.5Sr0.5Co0.8Fe0.2O3 − δ (BSCF) composite membranes fabricated using a conventional sintering technique. GDC/BSCF composite membranes with a relative density > 95% could be obtained when a green compact of BSCF and GDC was sintered at 1150 °C for 5 h. It appears that GDC serves as a grain growth inhibitor because the average grain size of the composite decreased with increasing GDC content. The oxygen permeability of the BSCF and GDC/BSCF composite membranes strongly depends on the grain size and membrane thickness. The addition of GDC to BSCF resulted in a small grain size, low thermal expansion coefficient and high hardness. However, it is believed that oxygen permeation was blocked by GDC, as the oxygen permeability decreased with increasing GDC content.