Electrical properties of yttrium doped strontium titanate with A-site deficiency as potential anode materials for solid oxide fuel cells

Yttrium doped strontium titanate with A-site deficiency ((Y0.08Sr0.92)1 − xTiO3 − δ) was synthesized by conventional solid state reaction. The deficiency limit of A-site in (Y0.08Sr0.92)1 − xTiO3 − δ is below 6 mol% in Ar/H2 (5%) at 1500 °C. The sinterability of (Y0.08Sr0.92)1 − xTiO3 − δ samples decreases slightly with increasing A-site deficiency level (x). The ionic conductivity of (Y0.08Sr0.92)1 − xTiO3 − δ samples increases while the electronic conductivity decreases with increasing A-site deficient amount. The defect chemistry analysis indicates that the introduction of A-site deficiency results in not only the increase of oxygen vacancy concentration but also the decrease of Ti3+-ion concentration. The latter plays the main role in the electrical conduction. (Y0.08Sr0.92)1 − xTiO3 − δ shows good thermal-cyclic performance in electrical conductivity and has an excellent chemical compatibility with YSZ electrolyte below 1500 °C.