过渡金属氧化物掺杂Ce0.8Nd0.2O1.9固体电解质的结构和电性能

摘要

采用溶胶凝胶法合成Ce0.8Nd0.2O1.9（NDC）粉体，分别将1％（x，摩尔分数）的过渡金属氧化物（TransitionalMetalOxides，TMOs）Ce0.8Nd0.2O1.9或CoO添加到NDC粉体中，经10MPa压片后于1300℃烧结6h。用X射线衍射（XRD）和场发射扫描电子显微镜（FE—SEM）对样品进行结构表征，采用交流阻抗谱（AC）测试样品导电性能。结果表明，Ce0.8Nd0.2O1.9或CoO对NDC均可有效促进样品的致密化，增加相对致密度和提高NDC的晶粒电导率；1％（x）MnO2或1％（x）CoO的掺杂对NDC的晶界电导率产生有害的影响，掺杂1％（x）FeO1.5对NDC晶界杂质SiO：有一定的清除作用，提高晶界电导率。Fe2O3不仅是一种良好的烧结助剂，而且是一种有效的晶界清除剂。%The precursor powder of Ce0.8Nd0.2Ol.9 （NDC） was prepared by the sol-gel method and 1 % （molar fraction, x） Transitional Metal Oxides （TMOs） MnO2, FeO1.5 or CoO were added to the NDC powder, respectively. After pressed under 10 MPa, the samples were sintered at 1 300℃ for 6 h. The characterizations focused on phase structure, electrical conductivity of all the samples were inves- tigated by X-ray diffraction （XRD）, field emission scanning electron microscopy （FE-SEM）. Electrical conductivity of the pellets was measured using AC impedance spectroscopy. The results showed that the MnO2, Fe2O3 or CoO could be more effective in promoting densification, increase relative density, increase the grain interior conductivity of the NDC. 1% （x） MnO2 or 1% （x） CoO additions have found to be detrimental to the grain boundary conductivity of the NDC, however, addition of 1%（x）FeO1.5 has a scavenging effect on SiO2 impurity, increase the grain-boundary conductivity. Therefore, these investigations have indicated that Fe2Oa is shown to be an effective sintering aid, as well as a grain boundary scavenger.