CeO 2 based materials doped with lanthanides for applications in intermediate temperature electrochemical devices

Abstract

The present work aims at the investigation of the influence of different dopants’ ionic radius and concentration on the lattice parameters and the density of Ce 1−xLn xO 2−δ ( x = 0–0.20; Ln = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb) solid solutions. Moreover, the temperature dependence of the linear expansion of Ce 0.8Ln 0.2O 2−δ ceramics is examined in the range of 300–1173 K and the respective thermal expansion coefficients are calculated. Finally, the total electrical conductivity of Ce 1−xLn xO 2−δ ( x = 0.15–0.20) and multi-component Ce (1−x)Ln x/2Ln’ x/2O 2−δ ( x = 0.20; Ln = Sm, La, Gd, Dy and Ln’ = Dy, Nd, Er, Y) systems is studied in a wide range of temperatures in air atmosphere, as well as in a wide range of oxygen partial pressures at 1023 K and 1173 K. According to the experimental results of the present work, at the highest examined temperature of 1173 K and in air atmosphere, the maximum values of total electrical conductivity are observed in the cases of Ce 0.8Nd 0.2O 2−δ and Ce 0.8Sm 0.2O 2−δ.