Phase Stability and Conductivity of Δ-Bi2O3With Mixture of Yttrium and Ytterbium Oxides

In this research bi2o3 was doped with mixtures of 8,10,12 and 18 mol% of y2o3 and yb2o3 in order to stabilize the δ-bi2o3 phase using solid state reaction technique. experimental samples were fabricated by isostatic pressing and sintering at 850sc for 24 h. x-ray diffraction analysis detected cubic phase (δ-bi2o3) as the sole stable crystalline phase in samples including 12 and 18 mol% of y2o3 and yb2o3. the tetragonal phase was also observed in samples with 8 and 10% mol additives. x-ray diffraction analyses on aged samples at 600 oc with 12 mol% additives revealed that the δ-bi2o3 phase was transformed to the tetragonal polymorph form. results of ionic conductivity measurements showed that samples with 12 mol% additives (88 mol% bi2o3,8 mol% y2o3 and 4 mol% yb2o3) had a higher ionic conductivity than the other samples.