Study on Lattice's Thermal Expansion Coefficients of La_0.7Sr_0.3MnO₃

Chu Gang^1,2, Zhai Xiujing¹, Bi Shiwen¹,  Fu Yan¹
(¹School of Materials & Metallurgy, Northeastern University, Shenyang 110004  ²Research Centre of Analysis and Test, Liaoning University of Petroleum & Chemical Technology,  Liaoning Fushun  113001)

Abstract The thermal expansion coefficients of lattice parameters a and c of La_0.7Sr_0.3MnO₃ were determined and discussed by means of dynamic high temperature powder X-ray diffraction in the temperature range from room temperature to 1200°C. We could be concluded by experimental result that there was linearity relation between expansion coefficients of lattice parameter and temperature. The thermal expansion coefficient values of a^a_T、a^c_T and a^V_T of La_0.7Sr_0.3MnO₃ lattice were 9.1×10^-6/°C、11.8×10^-6/°C and 29.8×10^-6/°C. From the powder X-ray diffraction analysis it also could be seen that there was no phase change or structure change in the temperature range showed above.
Key words  Solid oxide fuel cell, Thermal expansion coefficients of tile lattice, Dynamic high temperature powder X-ray diffraction

La_0.7Sr_0.3MnO₃晶格热膨胀系数的测定

储 刚^1,2  翟秀静¹  毕诗文¹  符 岩¹
(¹东北大学材料与冶金学院  沈阳  110004  ²辽宁石油化工大学分析测试研究中心  辽宁抚顺  113001)

摘要  采用动态高温粉末Ｘ射线衍射技术，对微波合成的产物La_0.7Sr_0.3MnO₃从室温到120°C之间的晶格热膨胀系数进行了测定。实验结果表明：在测试温度范围内，La_0.7Sr_0.3MnO₃的晶格膨胀系数与温度呈线性关系。微波法合成的La_0.7Sr_0.3MnO₃的晶格热膨胀系数为：a^a_T=9.1×10^-6/°C、a^c_T=11.8×10^-6/°C和a^V_T=29.8×10^-6/°C。在实验温度区间内未发现样品有明显的相变或结构转变现象。
关键词  固体氧化物燃料电池  晶格热膨胀系数  动态高温粉末X射线衍射

储刚   男，40岁，博士生，高级工程师，从事仪器分析方法的研究和应用。
国家自然科学基金资助项目(50174016)
2003-03-28收稿，2003-07-27修回

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