Synthesis, structure and electrical conductivity of BaZr1-xDyxO3-δ ceramics

Dy3+-doped barium zirconate ceramics, BaZr1-xDyxO3-delta (x = 0, 0.05, 0.10, 0.15, 0.20), have been synthesized by pressureless-sintering method at 1973 K for 1011 in air. The structure and electrical conductivity of BaZr1-xDyxO3-delta ceramics were investigated by means of X-ray diffraction, scanning electron microscopy and complex impedance spectroscopy. BaZr1-xDyxO3-delta ceramics exhibit a cubic perovskite structure. The total conductivity of BaZr1-xDyxO3-delta ceramics obeys the Arrhenius relation, and gradually increases with increasing temperature from 723 to 1073 K. The BaZr0.90Dy0.10O3-delta ceramic exhibits the highest total conductivity at 1073 K. The measured total conductivities of the BaZr0.90Dy0.10O3-delta ceramic in wet hydrogen (4% H2O/H-2) and in air are 7.90 x 10(-3) S cm(-1) and 7.31 x 10(-3) S cm(-1) at 1073 K, respectively. The activation energy of BaZr1-xDyxO3-delta (x = 0.10, 0.15, 0.20) ceramics is clearly lower than that of undoped BaZrO3 ceramic in both wet hydrogen and air atmospheres, and it can be concluded that the Dy3+-doped BaZr1-xDyxO3-delta (x = 0.10, 0.15, 0.20) ceramics are potential proton conductors. (C) 2012 Elsevier Ltd. All rights reserved.