非晶态B_2O_3-0.7Li_2O-0.7LiCl电导率频谱的研究

STUDY ON THE FREQUECY DEPENDENCE OF THE CONDUCTIVITY OF AMORPHOUS B_2O_3-0.7Li_2O-0.7LiCl

本文对非晶态快离子导体的B_2O_3-0.7Li_2O-0.7LiCl的电导率与外电场频率的关系进行了研究。结果表明:在较宽的频率范围内,样品的体电导约等于总电导;电导率频谱在中频段有一平台,在高频段上升,而且温度越高,开始上升的频率也越高。这一结果使电导率的测定有可能简化,即可以采用交流电桥法或在某一合适频率下采用交流伏安法直接测量样品的总电导或总导纳的模值作为体电导的值,从而求得电导率。本文考虑到非晶态结构的长程无序对离子迁移的影响,从局域极化的角度讨论了电导率频谱的特点及其同温度的关系。

The relationship of the conductivity with frequency for an amorphous fast lithium ion conducting material B2O3-0.7Li20-0.7LiCl was studied. The results showed that: in a quite wide frequency range the bulk conductance was equal to the total conductance for the specimens; the frequency spectra of the conductivity showed a plateau and a rise in the intermediate and higher frequency range, respectively; and the frequency at which the conductivity began to increase became higher with rising of temperature. As a result of the features of such amorphous material, the measurement of the conductivity may be carried out by use of the a.c. bridge or the a.c. V-A method and thus be simplified. Considering the effect of the long range disorder in the non-crystalline solid on the ionic transport, we praposed a mechanism of the local polarization and explained the features of the spectra of conductivity and its dependence on temperature.