Co-precipitation synthesis of alumina doped yttria stabilized zirconia

Abstract

Co-precipitation method is applied to fabricate different amount of Al2O3–doped yttria stabilized zirconia (YSZ). The crystal phase, microstructure and electrical properties of the sample with access of Al2O3 are studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS), simultaneously a comparison is made with pure YSZ. When doping weight percentage of Al2O3 varies from 0 to 4%, the grain size decreases and existence of Al2O3 does not introduce new phase but pure cubic structure of YSZ can be observed. The lattice parameter increases first until doping 1 wt% Al2O3, then decreases with more doping amount. YSZ doped with different amount of Al2O3 has different ionic conductivity. As YSZ is doped with 0.5 wt%, 2 wt%, 3 wt% or 4 wt% Al2O3, the total ionic conductivity for each sample is lower than pure YSZ. Among all of the samples, the highest conductivity value belongs to the specimen of YSZ doped with 1 wt% Al2O3 owing to increased grain boundaries, reaching to 0.0334 S cm−1.