Mixed conductivity and electrode properties of Mn-doped Bi–Sr–Fe-based perovskite-type oxides

• A change in the crystal symmetry of Bi0.7Sr0.3Fe1 − xMnxO3 − δ between x = 0.2 and 0.3
• Mn-doped BSF favors electronic defect compensation.
• Ionic defects play an important role on the electrode properties of BSF.
• Thermal expansion coefficients of BSF and BSFM55 are below14 × 10− 6 K− 1.

The Fe-site of Bi0.7Sr0.3FeO3 − δ (BSF) was doped with manganese to determine any changes in the charged defects and understand how this change affects the electrode properties of this material. The electrical conductivity and oxygen permeability results suggest that Mn-doping effectively improves the electronic compensation of BSF, which is energetically favored by ionic compensation. In terms of electrode properties, 50 mol% Mn-doped BSF (BSFM55) showed more than one order of magnitude greater electrode resistance than BSF, suggesting that kinetics related to ionic defects plays a more important role than electronic defects in determining the properties of Bi–Sr–Fe based perovskite oxides.