Ce0.8Sm0.2O1.9基纳米复合材料的共沉淀合成与氧离子导电性

用化学共沉淀法制备了Ce_0.8Sm_0.2O_1.9-La_9.33Si₆O₂₆纳米复合氧离子导电材料，通过X射线衍射和透射电子显微镜对合成材料的相结构进行了分析，利用交流阻抗分析测试研究了材料的离子导电性. 结果表明，纳米复合材料的煅烧粉末的平均晶粒尺寸为20nm、烧结陶瓷体的平均晶粒尺寸为44nm；700℃时，纳米复合导电体的离子导电率为0.25Ω/cm；在整个测试温度范围内，纳米复合导电体比纯La_9.33Si₆O₂₆提高了3个以上数量级，并高于纯相Ce_0.8Sm_0.2O_1.9的导电性.

Coprecipitation Synthesis and Oxide Ionic Conductivities of Ce0.8Sm0.2O1.9-based Nanocomposite Materials

Ce_0.8Sm_0.2O_1.9-La_9.33Si₆O₂₆ nanocomposite materials were prepared by a two-step coprecipitation synthesis process. Phases and microstructure were investigated by X-ray diffraction and transmission electron microscope. Conductivities were measured by an A.C. impedance measurement system. The results show that the calcined nanocomposites have average grain size of 20nm and the sintered bulks have average grain size of 44nm. The oxide ion conductivity of the nanocomposite material is 0.25Ω/cm at 700℃.The conductivities of the nanocomposites are 3 orders higher than that of pure La_9.33Si₆O₂₆ ceramics, which are also higher than that of Ce_0.8Sm_0.2O_1.9 conductor in the test temperatures range. The conducting mechanisms for the nanocomposite ionic conductors are discussed.