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

Abstract Dy 3+ -doped barium zirconate ceramics, BaZr 1– x Dy x O 3– 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 BaZr 1– x Dy x O 3– δ ceramics were investigated by means of X-ray diffraction, scanning electron microscopy and complex impedance spectroscopy. BaZr 1– x Dy x O 3– δ ceramics exhibit a cubic perovskite structure. The total conductivity of BaZr 1– x Dy x O 3– δ ceramics obeys the Arrhenius relation, and gradually increases with increasing temperature from 723 to 1073 K. The BaZr 0.90 Dy 0.10 O 3– δ ceramic exhibits the highest total conductivity at 1073 K. The measured total conductivities of the BaZr 0.90 Dy 0.10 O 3– δ ceramic in wet hydrogen (4% H 2 O/H 2 ) 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 BaZr 1– x Dy x O 3– δ ( x  = 0.10, 0.15, 0.20) ceramics is clearly lower than that of undoped BaZrO 3 ceramic in both wet hydrogen and air atmospheres, and it can be concluded that the Dy 3+ -doped BaZr 1– x Dy x O 3– δ ( x  = 0.10, 0.15, 0.20) ceramics are potential proton conductors.