Synthesis and characteristics of nanocrystalline YSZ powder by polyethylene glycol assisted coprecipitation combined with azeotropic-distillation process and its electrical conductivity

Nanoscale 8 mol% yttria stabilized zirconia (YSZ) powders were prepared by polyethylene glycol (PEG-1540) assisted coprecipitation coupling with azeotropic distillation drying process. The role of PEG and azeotropic-distillation on the morphology and particle size of YSZ was studied. Thermogravimetry and X-ray diffraction results showed that azeotropic-distillation could reduce the formation temperature of YSZ phase. X-ray patterns of the YSZ powders revealed that the crystallite size of the powders increases with increasing calcination temperature, which is consistent with transmission electron microscopy observations. The sintering behavior and the ionic conductivity of the pellets prepared from YSZ powders calcined at 800 °C were also studied. At sintering temperatures ≥1400 °C, more than 99% of the relative density was obtained. The alternating-current impedance spectroscopy results showed that the YSZ pellet sintered at 1450 °C has ionic conductivity of 0.0726 S cm−1 at 800 °C in air. The present work results have indicated that the PEG assisted coprecipitation combined with azeotropic-distillation drying process is an alternative method to synthesize yttria stabilized zirconia powders with a high sinterability and a good ionic conductivity.