EFFECT OF (Bi2O3)0.75(Y2O3)0.25 ADDITION ON MICROSTRUCTURES AND IONIC CONDUCTIVITIES OF CODOPED ZIRCONIA

Variation of microstructures and ionic conductivities in (Bi2O3)(0.75)(Y2O3)(0.25) (YSB) modified electrolyte of 8 mol% Y2O3 stabilized zirconia (8YSZ) and YSB modified codoped zirconia (ZrO2)(0.92)(Y2O3)(0.075)(MgO)(0.005) (YSZM) is investigated in this work. The results demonstrated that a small amount of delta-YSB addition is effective in reducing the sintering temperature of 8YSZ from 1500 to 1200 degrees C and promoting the densification rate of ceramics. Compared to 8YSZ electrolyte, it is interesting that a very limited amount of monoclinic ZrO2 was observed due to the MgO stabilizer in YSB modified codoped zirconia electrolyte. Besides, enhancement of ionic conductivity in delta-YSB modified codoped zirconia is evidently increased by 67% in comparison to the specimen of 8YSZ electrolyte.