Effects of Yb-Concentration on the Proton Conductivities of Low Temperature Sinterable Barium Zirconate Ceramics

Abstract

The 10？25mol% Yb-doped BaZrO3 ceramics having relative densities higher than 98% were obtained by the stoichiometric addition of 4 mol% ZnO as a sintering aid and then sintering at 1300°C for 10 hours. The crystal structure of the 10 mol% Yb-doped BaZrO3 ceramics was mono-clinic (space group: Pm), while the crystal structures of the 15？25 mol% Yb-doped BaZrO3 ceramics were cubic (space group: Pm3m). When the crystal structures were cubic, the activation energy of the proton conductivities increased as the Yb-concentration increased. Due to the high activation energy, the proton conductivities of the 25 mol% Yb-doped BaZrO3 ceramics were significantly lower than those of the 10？20 mol% Yb-doped BaZrO3 ceramics, especially as the temperature decreased. ？ 2010, The Resources Processing Society of Japan. All rights reserved.