多晶Sr_(0.69)La_(0.31)F_(2.31)固体电解质材料的制备

Synthesis of MultiCrystal Sr0.69La0.31F2.31 Solid Electrolyte

采用共沉淀法直接合成了Ｓｒ０．６９Ｌａ０．３１Ｆ２．３１固溶体粉末。Ｘ射线衍射分析表明该固溶体为ＳｒＦ２的立方结构，Ｌａ进入ＳｒＦ２晶格，晶格常数ａ＝０５８４３ｎｍ，比纯ＳｒＦ２立方结构的晶格常数（ａ＝０５８００ｎｍ）略大。电子探针扫描分析表明，该共沉淀Ｓｒ０．６９Ｌａ０．３１Ｆ２．３１固溶体成分均匀，Ｓｒ，Ｌａ元素均匀分布。用交流阻抗谱法测定了Ｓｒ０．６９Ｌａ０．３１Ｆ２．３１固体电解质材料的阻抗谱，在７００℃以上该材料表现出均匀性和各向同性，可近似看作立方单晶。测得不同温度的电导率。

The solid solution of Sr0.69La0.31F2.31 was made by coprecipitation method. The Xray analysis results show that the solid solution of Sr0.69La0.31F2.31 has SrF2 cubic structure with the lattice constant of 05843 nm, which is larger than the lattice constant of 05800 nm of pure SrF2. The electronic probe scanning results show that the elements of Sr and La are distributed homogenously in solid solution. The complex impedance of solid electrolyte Sr0.69La0.31F2.31 was measured by AC method. It is revealed that when the temperature is higher than 700 , the solid electrolyte is homogeneous and isotropic and it can be supposed to be a cubic single crystal. The ionic conductibility was measured at different temperatures. The relationship between conductibility and temperature is shown as lg=414-367(103 /T), and the conductive activation energy is Ea=073 eV.