Mixed ionic-electronic conducting (MIEC) ceramics as oxygen transport membranes (OTMs) can provide high oxygen permeation rates at comparably low energy demands. For this purpose, Ba₀.₅Sr₀.₅Co₀.₈Fe₀.₂O₃₋δ (BSCF) shows the best performance under ideal operating conditions. Thermal and chemical stability investigations, electrical behavior σ(T,pO₂,t), and oxygen exchange parameter extraction by means of electrical conductivity relaxation resulted in a far better understanding of the BSCF system
