摘要
用传统固相烧结法制备试样并研究钡含量对电导率的影响。综合运用XRD、SEM、EIS和密度测试对试样进行表征。XRD衍射分析表明，合成物质基本为石榴石结构，当钡含量过多时，出现二次相。立方晶格常数随着钡含量的增大而增大，当x〉1时，变化无规律。测试了试样在20～250℃范围内的交流阻抗，实验结果表明，电导率随着X的增大而增大，并在X-1时达到最大值（8．77×10^-6S／cm，20℃），继续增大X电导率反而降低。活化能随着X的增大而减小，并在X-1时达到最小值（0．41eV），X继续增大活化能反而增大。Li6BaLa2Ta2O12的SEM照片中烧结粉末颗粒不均匀，有团聚现象，相对密度为80．7％。
The effect of barium content on the conductivity of samples prepared by conventional solid state reaction procedure was studied. The samples were characterised by XRD, SEM, density and ionic conductivity measurement. Powder X-ray diffraction data of Li6 BaxLa3-xTa2 O12. 5- 0.5x（x=0-2） indicate that single phase oxides with garnet-like structure exist over the compositional, while for x is larger, the presence of second phase in addition to the major garnet like phase is observed. The cubic lattice parameter increases with increasing bari- um content, the change is irregular when x〉1. The impedance plots of Li6BaxLa3-y ,Ta2O12. 5-0.5x（x=0-2） sam7 ples obtained at the temperature between 293 and 523K indicate that ionie conductivity increases with increasing the amount of barium and reaches a maximum（8.77）K 10 -6S/era, 20℃） at x=1 and then decreases with further increase in x in Li6 Bax La3-xTa2 O12.5-0.5x （x=0 2）. The activation energy decreases with increasing barium content and reaches a minimum（0.41eV） at x= 1 and then increases with further increase in x. Scanning electron microscope of sintered powder（x=1） shows that there is a non-uniform microstructure because of agglomera- tion. Relative density of sample（x=1） is 80.7%.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2011年第B04期350-353,357,共5页
Journal of Functional Materials
基金
中国矿业大学科研基金资助项目(ZX280)
中国矿业大学攀登资助项目(ON090237)
国家大学生创新性实验资助项目(11-01513)
关键词
石榴石结构
离子电导率
无机固态电解质
缔合缺陷
置换
garnet-like structure
ionic conductivity
inorganic solid electrolyte
association defect
substitution
