Structure and electrical conductivity of BaCe0.85Ln0.15O3-δ (Ln = Gd, Y, Yb) ceramics

BaCe(0.85)Ln(0.15)O(3-delta) (Ln = Gd, Y, Yb) ceramics are synthesized by the solid state reaction method. All of BaCe(0.85)Ln(0.15)O(3-delta) ceramics are composed of a single perovskite-type phase. The grain size of BaCe(0.85)Ln(0.15)O(3-delta) (Ln = Gd, Y, Yb) ceramics decreases with decreasing the ionic radius of doped cations. BaCe(0.85)Ln(0.15)O(3-delta) ceramic has the highest total conductivity at 1073 K in both 4% H2O-saturated H-2 and air among three kinds of BaCe(0.85)Ln(0.15)O(3-delta) ceramics: Total conductivities of BaCe(0.85)Ln(0.15)O(3-delta) and BaCe(0.85)Ln(0.15)O(3-delta) ceramics exceed 0.01 S cm(-1) in both 4% H2O-saturated H-2 and air above 773 K. The pre-exponential factors and activation energies of BaCe(0.85)Ln(0.15)O(3-delta) ceramics are similar both in 4% H2O-saturated H-2 and in air. The crystal structure, relative density and grain boundary area are the main influencing factors on electrical conductivity of doped barium cerates. (c) 2013 Elsevier Ltd. All rights reserved.