纳米级钇稳定氧化锆的制备与电性能表征

摘要

：以共沸蒸馏过程辅助的化学方法制备了纳米级的钇稳定氧化锆(YSZ)粉体.结rn果表明共沸蒸馏的方法有效地实现了沉淀的完全脱水，从而阻止了颗粒问的硬团聚.rnX射线衍射研究指出共沉淀物转变为立方相的最低温度为600℃.X射线衍射谱和高rn分辨透射电镜照片均显示在600℃下灼烧得到的粉体的粒径为6nm，而由BET比表面rn积测定计算所得到的粉体粒径则为11nm，从而确定团聚为软团聚.YSZ样片在rn1500℃下烧结5h得到了相对密度为94.8%的烧结体.以交流阻抗谱技术研究在空气rn和氩气气氛中材料的电导率，在900℃空气气氛下测得的电导率为0.056S·cm-1，而rn在氩气气氛下可达到0.067S·cm-1，显著高于用单纯共沉淀法制备的YSZ样片的电rn导率(0.009 S·cm-1)及用Plaster casting法制备的电导率(0.028S·cm-1).而电导活化rn能为0.88-0.89eV，较文献报导值低.%Nanoscale yttria doped zirconia powders are prepared by coprecipitation route aided by the rnazeotropic distillation process. As a result, hydrous zirconia are dehydrated effectively and the formarntion of hard agglomerates is prevented completely. Powder X-ray diffraction is carried out to testify the rnlowest calcination temperature for precipitate powders to turn into cubic phase with the value of 600℃.rnPowder X-ray diffraction, BET method and transmission electron microscopy were performed to characrnterize the powder properties. After being calcined at 600℃ for 2h, the average powder size was about rn6nm calculated from XRD spectra and HRTEM photo, while by BET method, the powder size is about rn11 m, which indicates that the aggregates are just soft aggregates. The density of YSZ pellets sintered rnat 1500℃ for 5h reached 94.8% and the electrical conductivity of the sintered pellets is 0. 056 S·rncm-1 in air and 0.067 S· cm-1 in Ar measured at 900℃ by a. c. impedance spectroscopy much higher rnthan the reported value[4,5].