Synthesis and ionic-electronic conductivity of A-site deficient (Y, In) co-doped SrTiO3 as novel materials for mixed conductor

A-site-deficient (Y, In) co-doped SrTiO3 was prepared by sol-gel method. A-site deficiency improved ionic conductivity and sinterability of materials. The ionic conductivity for (Y0.08Sr0.92)0.93Ti0.92In0.08O3−δ was 6.5 × 10−3 S cm−1 and increased about 169% compared with (Y0.08Sr0.92)0.97Ti0.92In0.08O3−δ at 800 °C. A-site deficiency decreased oxygen migration energy, therefore enhancing the conduction of oxygen ions. The optimized (Y0.08Sr0.92)0.97Ti0.92In0.08O3−δ sample exhibits an electrical conductivity in the order of 0.06-0.08 S cm−1 at 100-900 °C. A possible charge compensation mechanism of A-site-deficient (Y, In) co-doped SrTiO3 is also discussed.