Investigation on Oxygen Chemical Diffusion Properties of Perovskite Oxides (La1−xPrx)0.6Sr0.4Co0.8Fe0.2O3−δ

Perovskite oxide samples of (La1−xPrx)0.6Sr0.4Co0.8Fe0.2O3−δ (x = 0.2, 0.4, 0.6, 0.8) are obtained by solid-state reaction method. The oxygen chemical diffusion properties of (La1−xPrx)0.6Sr0.4Co0.8Fe0.2O3−δ are determined by electrical conductivity relaxation technique. The results show that the conductivity of (La1−xPrx)0.6Sr0.4Co0.8Fe0.2O3−δ increases with the increase of oxygen partial pressure. The (La1−xPrx)0.6Sr0.4Co0.8Fe0.2O3−δ samples have a high oxygen chemical diffusion coefficient, which decreases linearly with a decrease in temperature and an increase in Pr content. The oxygen chemical diffusion coefficient Dchem remains fairly constant at high PO2. The oxygen chemical diffusion coefficient is the highest for (La1−xPrx)0.6Sr0.4Co0.8Fe0.2O3−δ with x = 0.2, and attains a value of 9.41 × 10−5 cm2 s−1 at 600 °C. This shows the material’s promise as a cathode material for intermediate temperature solid oxide fuel cells.