Preparation and electrical conductivity of BaZr1-xRxO3-α (R = Sc, Y, Ho, Dy, Gd, In)

The influence of process parameters on the density of BaZr0.9Y0.1O3 proton-conductings ceramics was investigated. Dense ceramics (94-96% of theoretical density) were obtained by synthesis from coprecipitated zirconium and yttrium hydroxides and barium carbonate, followed by sintering at 1700 degreesC. The conductivity of BaZr0.93R0.07O3-alpha (R = Sc, Y, Ho, Dy, Gd, In) was measured as a function of temperature and oxygen partial pressure and was found to decrease in the order Y > Ho > Sc > Dy, In > Gd. In air, these materials are hole-ion conductors. At 800 degreesC, BaZr0.93Y0.07O3-alpha has an ionic transference number of 0.16 and ionic conductivity of 3.6 x 10(-4) S/cm.