Acta Phys. -Chim. Sin. ›› 2005, Vol. 21 ›› Issue (12): 1357-1362.doi: 10.3866/PKU.WHXB20051206

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Synthesis and Properties of La0.5RE0.3Sr0.2FeO3－δ (RE = Nd, Ce, Sm) System with Two Rare Earths for Cathodes

CHEN Yong-Hong;WEI Yi-Jun;ZHONG Hong-Hai;GAO Jian-Feng;LIU Xing-Qin;MENG Guang-Yao   

  1. 1Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026; 2Center of Experiment and Communication, Huainan Normal College, Huainan 232001
  • Received:2005-04-21 Revised:2005-06-24 Published:2005-12-15
  • Contact: LIU Xing-Qin E-mail:xqliu@ustc.edu.cn

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Abstract: Two rare earths composite oxides of La0.5RE0.3Sr0.2FeO3－δ(RE = Nd, Ce, Sm) with A-site doped Sr2+ samples were synthesized by Glycine-Nitrate processes (GNP). The formation process of the perovskite structure was analyzed by means of X-ray powder diffraction and TG-DSC. The relative density of the ceramics was measured by Archimedes method, and the electrical conductivity of the samples was studied by four-probe technique. The results show that the sample for RE = Nd presents a single perovskite-type phase with a cubic symmetry after sintering at 1200 ℃ for 2 h, while the samples with Ce doped showed a separated cubic phase of CeO2, and the specimen doped with Sm is a cubic perovskite-type phase accompanied by some faint impure peaks. The electrical conductivity of La0.5Nd0.3Sr0.2FeO3－δ (LNSF) sample obtained from being sintered at 1250 ℃ for 2 h was over 100 S•cm-1, significantly higher than that of the La0.5Ce0.3Sr0.2FeO3－δ(LCSF) and La0.5Sm0.3Sr0.2FeO3－δ (LSSF) at the same conditions. The results indicate that La0.5Nd0.3Sr0.2FeO3－δ may be a suitable cathode material for intermediate temperature SOFC.

Key words: La0.5RE0.3Sr0.2FeO3－δ(RE = Nd, Ce, Sm), SOFC, Perovskite-type, Cathodes