The structural and conductivity evolution of fluorite-type Bi2O3–Er2O3–PbO solid electrolytes during long-term annealing (original) (raw)

Quenched-in fcc fluorite-type materials in the Bi 2 O 3 -Er 2 O 3 -PbO system were annealed in air at 500 and 600°C for up to 2000 h. Each material experienced a conductivity-lowering structural transformation, thus making them unsuitable for use in SOFCs. For example, the materials (BiO 1.5 ) 0.80 (ErO 1.5 ) 0.20−x (PbO) x , x = 0.03, 0.06 and 0.09, underwent a fluorite-type to tetragonal transformation during annealing at 500°C due to 〈100〉 oxide-ion vacancy ordering, and the rate of conductivity decay at 500°C increased with increasing Pb 2+ /Er 3+ ratio.