Dy doped SrTiO3: A promising anodic material in solid oxide fuel cells

The perovskite-type oxides, having a general formula ABO3, are promising candidates for anode materials in solid oxide fuel cells. In particular, doped SrTiO3 based perovskites are potential mixed ionic- electronic conductors and they are known to have excellent thermal and chemical stability along with carbon and sulfur tolerance. In this work, DyxSr1-xTiO3-? system with x = 0.03, 0.05, 0.08 and 0.10 is studied to understand the influence of Dy content on its structural and electrical behavior. Properties are measured, both in air and hydrogen atmosphere, and discussed in detail. Results show that DyxSr1-xTiO3-? powders with x <= 0.05, are single phase, while for x >= 0.08 a small amount of secondary phases is formed. In air, the conductivity is predominantly ionic type for <= 0.05, becoming electronic for x >= 0.08. It is observed that conductivity, for each composition, increases passing from air to hydrogen and activation energy decreases. Dy0.05Sr0.95TiO3-? shows the highest conductivity in air whereas Dy0.08Sr0.92TiO3-? in H2 atmosphere. Degradation observed by XRD is negligible for x <= 0.05 but increases with higher Dy content.