Mixed oxide ion and electronic conductivity in perovskite-type SrSnO₃ by Fe substitution

The electrical conductivity properties of Fe-substituted SrSnO₃ perovskite-type oxides as a function of temperature and oxygen partial pressure are presented. SrSn_1-xFe_xO_3-δ (0≤x≤1) was prepared by conventional solid state reaction in air using SrCO₃, SnO₂ and FeC₂O₄ · 2H₂O. The total electrical conductivity increases with increasing Fe content. Compounds containing low Fe contents (x<0.5) are mixed oxide ion and electronic conductors in the oxygen partial pressure range between 10^-23 and 0.21 atm with predominant n-type and p-type electronic conduction at low and high oxygen partial pressure, respectively. SrSn_1-xFe_xO_3-δ with high Fe-content (x > 0.5) is found to be a predominant electronic conductor over the entire oxygen partial pressure regime (10^-23-0.21 atm). The average oxide ion transference number is found to be in the range 0.1-0.5 at 600-850 °C for x = 0.1-0.2.