Ce0.8Sm0.2O1.9-La0.9Sr0.1Ga0.8Mg0.2O2.85复合材料的制备与导电性

摘要

为研究复合材料氧离子导电体的导电特性,采用化学共沉淀法制备Ce0.8Sm0.2O1.9-La0.9Sr0.1Ga0.8Mg0.2O2.85纳米复合粉体,并获得复合陶瓷材料.通过X线衍射仪和扫描电子显微镜对复合材料的物相组成与微观结构进行分析,利用交流阻抗测试研究材料的离子导电性.研究结果表明:煅烧复合粉体的平均晶粒尺寸为15 nm；复合材料的导电性均明显高于复合组元的单相材料的导电性；La0.9Sr0.1Ga0.8Mg0.2O2.85中La2O3过量3％(质量分数)的复合材料体现最好的导电性,在700℃时的导电率为0.106 S/cm.通过交流阻抗谱分析晶粒、晶界特性,探讨复合电解质材料的导电机理.%In order to study the conduction characteristic of composite oxide-ionic conductors, Ceo.gSmo2O1.9-Lao9Sro1Gao.8Mgo.2O2.85 nano-composite powders were prepared by a co-precipitation method and the related composite ceramics were obtained. The phase component and microstructures of the composite materials were investigated by using X-ray diffraction and scanning electron microscopy, respectively. AC impedance test was employed to analyze the conductivities of the composites. The results show that nano-composite powders with the average grain size of 15 nm were obtained, and the conductivities of composite materials are much higher than those of the pure phase of composite component. The oxide-ionic conductivities of the composite material with 3% excess of La2O3 in Lao.9Sro1Gao.gMgo2O2.85 show the highest ones, and the conductivity is 0.106 S/cm at 700 °C. By analyzing grain and grain-boundary effects from the AC impedance spectroscopes, the conduction mechanism of the composite materials was discussed.