Ce_(0.8)Nd_(0.2-x)Pr_xO_(1.9)固溶体的Raman光谱与阻抗谱  

RAMAN SPECTRA AND IMPEDANCE SPECTRA OF SOLID SOLUTION Ce_(0.8)Nd_(0.2-x)Pr_xO_(1.9)

作　　者：林晓敏[1,2] 万鹏[1] 朱丽丽[1] 闫石[1] 苏文辉[2,3,4] 

机构地区：[1]北华大学物理学院,吉林132013 [2]吉林大学物理学院,长春130023 [3]哈尔滨工业大学,凝聚态科学与技术中心,哈尔滨150001 [4]中国科学研究院,国际材料物理中心,沈阳110015

出　　处：《硅酸盐学报》2009年第9期1469-1474,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(10374022);吉林省教育厅科研基金(200690)资助项目

摘　　要：用溶胶-凝胶法合成了氧化铈稀土双掺杂Ce0.8Nd0.2-xPrxO1.9(x=0,0.10,0.15)固溶体。用X射线衍射(X-ray diffraction,XRD),Raman光谱和交流阻抗谱研究了固溶体的结构和导电性。XRD结果表明:经800℃焙烧所有的样品都形成了单相立方萤石结构,平均晶粒尺寸为22～32nm。X射线光电子能谱结果表明:样品中镨离子以混合价态(Pr3+和Pr4+)存在。Raman谱结果表明:Ce0.8Nd0.2-xPrxO1.9具有氧缺位的立方萤石结构,Pr离子的掺杂有利于氧缺位增加。阻抗谱表明:稀土双掺杂Ce0.8Nd0.2-xPrxO1.9(x=0.10,0.15)的电导率高于稀土单掺样品Ce0.8Nd0.2O1.9的,Ce0.8Nd0.05Pr0.15O1.9的电导率最大,在600℃时的电导率为2.63×10-2S/cm,导电活化能Ea=0.40eV(600～800℃),Ea=0.62eV(400～600℃),与Ce0.8Nd0.05Pr0.15O1.9材料内部更多的氧离子缺位和小极化子电子导电相关。Rare earth co-doped ceria Ce0.8Nd0.2–xPrxO1.9（x = 0,0.10,0.15） solid solutions were synthesized by the sol-gel method. The structure and conductivity were characterized by X-ray diffraction（XRD） and Raman and impedance spectra. The XRD results show that all powders calcined at 800 ℃ are crystallized in a single cubic fluorite structure. The average grain sizes are between 22 nm and 32 nm. X-ray photoelectron spectroscopy analysis indicates that the mixed valence Pr^3＋ and Pr^4＋ coexisted in the solid solutions. The Raman spectra analysis reveals that the solid solution Ce0.8Nd0.2-xPrxO1.9 has a cubic fluorite structure with oxygen vacancies. The oxygen vacancy concentration is increased by doping Pr in Ce0.8Nd0.2-xPrxO1.9. Impedance spectra shows that the conductivity of rare earth co-doped ceria Ce0.8Nd0.2-xPrxO1.9 （x = 0, 0.10, 0.15） is higher than that of single rare earth doped ceria Ce0.8Nd0.2O1.9. The results also show that Ce0.8Nd0.05Pr0.15O1.9 possess maximum conductivity. At 600 ℃, the conductivity is 2.63× 10^-2 S/cm and activation energy Ea = 0.40eV（600-800 ℃）, Ea=0.62eV （400-600 ℃）, which is assigned to the higher oxygen vacancy concentration and the hopping electron transition of small polarons in the sample Ce0.8Nd0.05Pr0.15O1.9.

关 键 词：铈钕镨化合物 氧缺位 RAMAN谱 阻抗谱 

分 类 号：O641.33[理学—物理化学]