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无机材料学报

无机材料学报

• 研究论文 • 上一篇    下一篇

钠快离子导体NaLaS2和NaLaS1.5Se0.5的合成及表征

孙军康, 黄富强, 杨建华, 刘战强

  

  1. 中国科学院 上海硅酸盐研究所高性能陶瓷与超微结构国家重点实验室, 上海 200050
  • 收稿日期:2007-04-23 修回日期:2007-08-13 出版日期:2008-03-20 网络出版日期:2008-03-20

Synthesis and Characterization of NaLaS2 and NaLaS1.5Se0.5 Sodium Fast Ionic Conductors

SUN Jun-Kang, HUANG Fu-Qiang, YANG Jian-Hua, LIU Zhan-Qiang   

  1. State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
  • Received:2007-04-23 Revised:2007-08-13 Published:2008-03-20 Online:2008-03-20

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摘要： 以Na2S、La和S或Se为原料在750℃下固相反应合成新型钠快离子导体NaLaS2和NaLaS 2. X射线衍射分析表明, NaLaS2 和NaLaS1.5Se0.5具有相同的晶体结构, 其空间群为FM3-M. 通过在0.1Hz～100kHz的频率范围交流阻抗谱的测试, 分析了这些快离子导体的离子导电性, 发现在相同的温度下NaLaS1.5Se0.5的电导率高于NaLaS2. NaLaS2在30和90℃时的电导率分别为3.65×10-5 和6.23×10-5S·cm-1, 而NaLaS1.5Se0.5在30和60℃时的电导率分别为8.11×10-5和1.37×10-4S·cm-1. 通过对合成物晶体结构的分析, 推测这两种化合物的导电率差异可能来自于Se2-离子较高的极化能力, 以及离子半径较大的Se2-引起的局部晶格扩大.

关键词: 快离子导体, 电导率, 活化能

Abstract: sodium fast ion conductors of NaLaS2 and NaLaS1.5Se0.5 were prepared by high temperature solid state reaction at 750℃. X-ray powder diffraction analysis confirms that NaLaS1.5Se0.5 is isostructural to NaLaS2 and NaLaSe2
(space group FM3-M). Their ionic conductive properties were investigated by AC impedance spectroscopy in the frequency range of 0.1Hz--100kHz at different temperatures. The conductivity of NaLaS1.5Se0.5 is higher than that of NaLaS2 at the same temperature. NaLaS 2 shows conductivity of 3.65×10-5S·cm-1 at 30℃ and 6.23×10-5S·cm-1 at 90℃, respectively; while NaLaS1.5Se0.5 displays higher conductivity of 8.11×10-5S·cm-1 at 30℃ and 1.37×10-4S·cm-1 at 60℃, respectively. This is probably due to the stronger polarization power of Se2--, the larger radius of Se2-, and subsequently the enlargement of local lattice.

Key words: fast ionic conductor, conductivity, activation energy

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