Journal of the American Ceramic Society, Vol.85, No.11, 2633-2636, 2002
Properties of ionic-conducting beta-Bi2O3 containing mixed dopants
beta-Bi2O3 compositions were prepared to evaluate the effect on properties of using mixed dopants. Baseline compositions containing 28 mol% of the alkaline-earth oxides CaO, SrO, or BaO were used for comparison. When the alkaline earths were combined in pairs to dope the bismuth oxide, the resulting properties were intermediate between the baseline end members. The data suggest that the transformation temperature for forming the high-conductivity beta(1) phase can be varied continuously over a temperature range of about 565degrees to 750degreesC. Utilization of additional additives having different ionic size or valence charge compared with the alkaline earths resulted in no observed property changes that could be attributed to the additive alone. The most important variables influencing the conductivity level and phase transformation temperature of beta-Bi2O3 were the type and the amount of the alkaline-earth dopant in the composition.