高级检索
无机材料学报

无机材料学报

• 研究论文 • 上一篇    下一篇

Pr0.6-xNdxSr0.4FeO3-δ体系复合氧化物的制备与表征

魏亦军1, 陈永红1,2, 刘杏芹2, 孟广耀2   

  1. 1. 淮南师范学院实验信息中心, 淮南 232001; 2. 中国科学技术大学材料科学与工程系, 合肥 230026
  • 收稿日期:2005-11-09 修回日期:2006-03-15 出版日期:2006-09-20 网络出版日期:2006-09-20

Synthesis and Characterization of Pr0.6-xNdxSr0.4FeO3-δ System Compounds

WEI Yi-Jun1, CHEN Yong-Hong1,2, LIU Xing-Qin2, MENG Guang-Yao2   

  1. 1. Center of Experiment and Communication, Huainan Normal College, Huainan 232001, China; 2. Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China
  • Received:2005-11-09 Revised:2006-03-15 Published:2006-09-20 Online:2006-09-20

PDF (PC)

1764

摘要： 采用柠檬酸-硝酸盐法合成了Pr0.6-xNdxSr0.4FeO3-δ(x=0.0~0.6)系列钙钛矿型复合氧化物粉体, 用
XRD、FT-IR、TD-DTA、SEM等对产物的形成过程、物性及微结构进行了表征. 结果表明, 所合成的系列样品1200C煅烧2h即形成立方钙钛矿结构
的单相固溶体. 用直流四端子法测量了烧结陶瓷体在中温(450~800℃)范围内的电导率, A位单一稀土元素的样品(x=0.0、0.6)及以Pr(x=0.1)或
Nd(x=0.5)为主的稀土复合氧化物, 其电导率均在150S cm-1以上,明显高于双稀土样品(x=0.2、0.3、0.4)的数值( σ=45~80S cm-1); x=0.2、0.3
、0.4三个样品电导率较低的原因, 与它们在同样烧结制度下的致密度低密切相关.该系列样品的电导率在650~700℃附近出现最大值, 低温段的导电行为符合小极化子导电机制.

关键词: 双稀土, Pr0.6-xNdxSr0.4FeO3-δ, 阴极材料, 钙钛矿, 电导率

Abstract: Pr0.6-xNdxSr0.4FeO3-δ(x=0.0~0.6)samples were synthesized by the citrate-nitrate method. The formation process of the perovskite-type phase and the microstructure of the samples were characterized by XRD, FT-IR, TG-DTA, and SEM. The results revealed that all the samples calcined at 1200℃ for 2h were single-phase solid solutions with cubic symmetry. The electrical conductivity of sintered ceramics at 450~800C were measured by four-probe technique. The results show that the specimens with single rare earth and the compounds with Pr or Nd as leading element at A-site have excellent electrical conductivity, the data are over 150S cm-1, clearly higher than that of two-rare earths specimens. The reason of decreasing electrical conductivity for 0.2≤x≤0.4 is correlated with lower relative density at the same sintering conditions. The maximum value of electrical conductivity for all samples occurred at about 600~700℃, and the electrical conductivity certified that the hopping of small polaron is the dominating mechanism below 650℃.

Key words: two rare earths, Pr0.6-xNdxSr0.4FeO3-δ, cathode materials, perovskite, electrical conductivity