高等学校化学学报

高等学校化学学报 ›› 2001, Vol. 22 ›› Issue (4): 531.

• 研究论文 • 上一篇    下一篇

纳米晶固溶体Ce0.8Nd0.2O2-δ的合成与表征

林晓敏1, 李莉萍1,2, 罗微3, 苏文辉1,4   

  1. 1. 吉林大学物理系;
    2. 吉林大学无机合成与制备化学教育部重点实验室;
    3. 吉林大学超硬材料国家重点实验室, 长春 130023;
    4. 中国科学院国际材料物理中心, 沈阳 110015
  • 收稿日期:2000-03-22 出版日期:2001-04-24 发布日期:2001-04-24
  • 通讯作者: 莉萍(1963年出生),女,博士,教授,从事极端条件下稀土固体物理研究.3现在北华大学师范学院物理系工作.
  • 基金资助:

    国家自然科学基金(批准号:19804005);吉林大学无机合成与制备化学教育部重点实验室资助课题

Synthesis and Characterization of Nanocrystalline Ce0.8 Nd0.2 O2-δ Solid Solution

LIN Xiao-Min1, LI Li-Ping1,2, LUO Wei3, SU Wen-Hui1,4   

  1. 1. Department of Physics;
    2. Key Lab of Inorganic Synthesisand Preparative Chemistry of the Educational Ministry;
    3. Key Lab of High Pressure, Jilin University, Changchun 130023, China;
    4. Center of International Material Physics Research, Academia Sinica, Shenyang 110015, China
  • Received:2000-03-22 Online:2001-04-24 Published:2001-04-24

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摘要： 利用溶胶-凝胶法合成纳米晶固溶体Ce0.8Nd0.2O2-δ.XRD测试表明,胶体经200℃烧结处理就可以得到晶粒尺寸为7.2nm的纳米晶,随烧结温度的升高,晶粒尺寸增大.EPR测试给出固溶体Ce0.8Nd0.2O2-δ存在少量的Ce3+离子.在纳米晶固溶体Ce0.8Nd0.2O2-δ的Raman光谱上观察到两个峰,低频的强峰为特征F2g振动谱带,高频谱带的出现与样品中存在氧缺位有关.固溶体晶粒尺寸的减小不但使F2g振动谱带红移,而且谱带明显宽化.复阻抗谱的测量表明,固溶体Ce0.8Nd0.2O2-δ具有氧离子导电特性.400和500℃时的电导率分别为4.55×10-4和2.65×10-3S·cm-1,活化能为0.82eV.

关键词: Ce0.8Nd0.2O2-&delta, , 离子价态, Raman光谱, 电导率

Abstract: The solid solution Ce0.8 Nd0.2 O2-δ was prepared by sol-gel method. The XRD measurements showed that the product obtained by sintering the fresh gel at 200 ℃ crystallized in a single fluorite structure and its grain size was calculated to be ca. 7.2 nm by Scherrer formula. With the increase of sintering temperature, the grain size of solution increases. Afew of Ce 3+ ions were detected by EPRmeasurement. The first-order Raman spectra of the solid solutions exhibited two peaks. The strong band F2g mode at a lower frequency is assigned to symmetric breathing mode of the oxygen atoms around cerium ions, while the weak band at ca. 570 cm-1 is related with the existence of oxygen vacancies. With the grain decrease, the F2g mode shifts to the lower frequency, while the half height width becomes broaden. The ionic conductivity for the solid solution Ce0.8 Nd0.2 O2-δ at 500 ℃( σ 500 ℃ ) is 2.65×10-3 S·cm-1, and the activation energy is 0.82 eV.

Key words: Ce0.8 Nd0.2 O2-δ, Ionic valency state, Raman spectrum, Conductivity

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