固体电解质Ce_(0.9)Er_(0.1-x)Pr_xO_(1.95+δ)的微观结构及电性能

采用柠檬酸溶胶-凝胶法制备了固体电解质Ce0.9Er0.1-xPrxO1.95+δ(x=0.02~0.08),利用X射线粉末衍射(XRD)、原子力显微镜(AFM)、拉曼光谱(Raman)、X射线光电子能谱(XPS)和交流阻抗谱研究了样品的微观结构和电性能.XRD结果表明,800℃煅烧的所有样品均形成了单相立方萤石结构;Raman光谱结果表明,Ce0.9Er0.05Pr0.05O1.95+δ具有氧缺位的立方萤石结构;XPS分析表明,Ce0.9Er0.05Pr0.05O1.95+δ存在氧缺位,Pr3+离子和Pr4+离子共存;AFM观测结果表明,1300℃下烧结的样品比1400℃下烧结的样品致密;交流阻抗谱结果表明,Pr掺杂量x=0.05时,Ce0.9Er0.05Pr0.05O1.95+δ的电导率最高(σ600℃=1.34×10-2S/cm,Ea=0.90 e V),比未掺杂Pr的Ce0.9Er0.1O1.95(σ600℃=8.81×10-3S/cm,Ea=0.92 e V)提高了52%,说明在Ce0.9Er0.1O1.95中适量掺杂Pr可提高材料的电导率,降低活化能.

Microstructure and Electrical Properties of Solid Electrolytes Ce0.9Er0.1-xPrxO1.95+δ

The microstructure and electrical conductivity of Ce0.9Er0.1-xPrxO1.95+δ(x=0—0.08) solid electrolytes synthesized by citric sol-gel method were characterized by means of X-ray diffraction(XRD), atomic force microscopy(AFM), Raman, X-ray photoelectron spectroscopy and impedance spectroscopy. XRD measurements show that all the samples calcined at 800 ℃ crystallize in single cubic fluorite structure. The Raman spectra indicate that the Ce0.9Er0.05Pr0.05O1.95+δ is cubic fluorite structure with oxygen vacancies. X-ray photoelectron spectroscopy analysis suggest that oxygen vacancies and the mixed valence Pr3+ and Pr4+ ions exist in Ce0.9Er0.05Pr0.05O1.95+δ. AFM results show that sample Ce0.9Er0.05Pr0.05O1.95+δ sintered at 1300 ℃ is denser than that sintered at 1400 ℃. The maximum conductivity of Ce0.9Er0.05Pr0.05O1.95+δ is found at x=0.05(σ600 ℃=1.34×10-2 S/cm, Ea=0.90 eV). The conductivity of Ce0.9Er0.05Pr0.05O1.95+δ increases by 52% in comparison with that of Ce0.9Er0.1O1.95 without Pr(σ600 ℃=8.81×10-3 S/cm, Ea=0.92 eV), which suggests that co-doping with appropriate ratio of Pr can further improve the electrical performance of Ce0.9Er0.1O1.95.