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

Dy3+-doped barium zirconate ceramics, BaZr1–xDyxO3–δ (x = 0, 0.05, 0.10, 0.15, 0.20), have been synthesized by pressureless-sintering method at 1973 K for 10 h in air. The structure and electrical conductivity of BaZr1–xDyxO3–δ ceramics were investigated by means of X-ray diffraction, scanning electron microscopy and complex impedance spectroscopy. BaZr1–xDyxO3–δ ceramics exhibit a cubic perovskite structure. The total conductivity of BaZr1–xDyxO3–δ ceramics obeys the Arrhenius relation, and gradually increases with increasing temperature from 723 to 1073 K. The BaZr0.90Dy0.10O3–δ ceramic exhibits the highest total conductivity at 1073 K. The measured total conductivities of the BaZr0.90Dy0.10O3–δ ceramic in wet hydrogen (4% H2O/H2) and in air are 7.90 × 10−3 S cm−1 and 7.31 × 10−3 S cm−1 at 1073 K, respectively. The activation energy of BaZr1–xDyxO3–δ (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–δ (x = 0.10, 0.15, 0.20) ceramics are potential proton conductors.