利用溶胶-凝胶方法合成了Ce0.8Pr0.2O2-δ固溶体,XRD结果表明,经200℃焙烧就已经形成立方萤石结构固溶体,晶粒尺寸为8.1nm,随焙烧温度的升高,晶粒尺寸增大。X射线光电子能谱(XPS)结果表明,样品中存在氧离子缺位,铈离子主要为Ce^4+离子,镨离子以混合价态Pr^3+和Pr^4+存在。固溶体Ce0.8Pr0.2O2-δ的拉曼谱(Rarnan)观察到4个峰,458和1140cm^-1峰为特征F2g振动谱带,较宽的570和187cm^-1峰对应氧离子缺位及引起的不对称振动。交流阻抗谱表明固溶体Ce0.8Pr0.2O2-δ在600℃时的电导率为1.44×10^-3S·cm^-1,活化能为Ea=0.67eV(650~800℃),Ea=0.91eV(400~600℃)。
The solid solution Ce0.8Pr0.2O2-δ was synthesized by sol-gel method. XRD measurement showed that solid solution Ce0.8Pr0.2O2-δ crystallized in cubic fluorite structure at 200 ℃. The grain size of the solution was 8.1 nm. The average grain size increased with temperature. XPS analysis suggested that oxygen vacancy, mixed valence Pr^3+/Pr^4+ ions and major Ce^4+ ions existed in the solid solutions. The Raman spectra of the solid solution Ce0.8Pr0.2O2-δ exhibitedfour peaks. The 458 and 1140 cm^-1 peaks were attributed to Raman active F2g mode assigned to symmetric breathing mode of oxygen atoms around cerium ions. The peaks at 570 and 187 cm^-1 were attributed to the asymmetric vibration caused by oxygen vacancies. Impedance spectra showed that the conductivity for Ce0.8Pr0.2O2-δ was 1.44×10^-3 S·cm^-1 at 600 ℃, and the activation energy was Ea = 0.67 eV (650 - 800 ℃ ), Ea = 0.91 eV(400 - 600 ℃).