High-temperature transport in perovskite-type Ca0.25Sr0.75Fe0.75Mo0.25O3 − δ

The comparative study of transport characteristics of SrFe0.75Mo0.25O3 − δ and Ca0.25Sr0.75Fe0.75Mo0.25O3 − δ was carried out in order to evaluate calcium substitution usability to improve functional properties of electrode materials based on SrFe1 − xMoxO3 − δ. The electrical conductivity in CaxSr1 − xFe0.75Mo0.25O3 − δ was measured as a function of oxygen partial pressure varying in the range of 10−21–0.5 atm at the temperature range of 750–950 °C. The thermogravimetric measurements have revealed that calcium substitution results in a decrease of oxygen content in SrFe0.75Mo0.25O3 − δ. The conductivity and oxygen content analysis has shown that calcium introduction in SrFe0.75Mo0.25O3 − δ provides about 30% conductivity increase under reducing conditions attributed to an increase in both concentration and mobility of n-type charge carriers. In contrast, hole conduction has been found unaffected by calcium content in CaxSr1 − xFe0.75Mo0.25O3 − δ. The improved electrical conductivity in Ca0.25Sr0.75Fe0.75Mo0.25O3 − δ under reducing conditions calls for testing this oxide as an anode material.