Effect of CaO addition on the structure and electrical conductivity of the pyrochlore-type GdSmZr2O7

Abstract: Polycrystalline GdSm1−x Ca x Zr2O7−x/2 (0≤ x ≤0.20) ceramics have been prepared by the solid-state reaction method. The effects of CaO addition on the microstructure and electrical properties of the pyrochlore-type GdSmZr2O7 ceramic were investigated. GdSm1−x Ca x Zr2O7−x/2 (x ≤0.05) ceramics exhibit a pyrochlore-type structure; however, GdSm1−x Ca x Zr2O7−x/2 (0.10≤ x ≤0.20) ceramics consist of the pyrochlore-type structure and a small amount of CaZrO3. The total conductivity of GdSm1−x Ca x Zr2O7−x/2 ceramics follows the Arrhenius relation, and gradually increases with increasing temperature from 723 to 1173K. GdSm1−x Ca x Zr2O7−x/2 ceramics are oxide-ion conductors in the oxygen partial pressure range of 1.0×10−4–1.0atm at each test temperature. The highest total conductivity is about 1.20×10−2 Scm−1 at 1173K for the GdSm0.9Ca0.1Zr2O6.95 ceramic. [Copyright &y& Elsevier]