一种测定某些离子导体的导电基本参数的新方法  

A NEW METHOD APPLIED TO SOME IONIC CONDUCTORS FOR MEASURING PARAMETERS OF IONIC CONDUCTION

作　　者：许政一[1] 凌亚文 杨华光[1] 

机构地区：[1]中国科学院物理研究所,北京100080

出　　处：《物理学报》1990年第11期1785-1790,共6页Acta Physica Sinica

基　　金：国家自然科学基金资助的课题

摘　　要：利用低频交变电场在某些离子导体中能引起偏振态改变的光衍射特性,发展了一种测量这些离子导体的导电基本参数的新方法,并且用它测定了α-LiIO_3单晶的基本离子导电参数,测得其载流子的迁移率激活能E_μ=0.36eV;夫仑克耳缺陷的形成能为E_M=0.59eV;300K时正、负载流子的数密度均为1.6×10^(17)Cm^(-3),相对浓度均为1.07×10^(-5);当所加电场反平行于晶体的自发极化强度时(将所加电压记为V_+),有效迁移率为μ_(eff)^+=3.9×10^(-8)cm^2s^(-1)V^(-1);当两者平行时(相应的电压记为V_-)有效迁移率为μ_(eff)^-=3.4×10^(-9)cm^2s^(-1)V^(-1);在交变电场与V_+对应的半周期内,离子至少需要跳跃7步才能在晶体中形成光栅,发生光衍射;而在另半个周期内,离子至少需要跳跃32步才能引起衍射光强的波动部分。In this paper, a new method applied to some ionic conductors for measuring fundamental parameters of ionic conduction was developed based on the phenomena of light diffraction produced by a laser beam through these ionic conductors under a low frequency AC field.The ionic conduction parameters of aaaa-LiIOs single crystal was measured by this method. The results are as follows. The activation energy of mobility Eμ=0.36eV. The formation energy of Frenkel defect EM =0.59 eV. At 300K, both the number densities of positive and negative carriers are 1.6×1017cm-3; their relative concentrations are 1.07×10'5; the effective mobility uuuuueff+ = 3.9×10-8cm2·s-1·V-1 as the DC field applied to the crystal is antiparallel to its spontaneous polarization (we denote the voltage as V+) the effective mobility μeff- = 3.4 × 10-9cm2·s-1·V-1 as they are parallel (we denote the voltage as V-). Under the action of an AC field, in the half period that is corresponding to V+, it at least need that the ion hops 7 steps to form a space grating, and in another half period ion at least hops 32 steps to cause an oscillating component in the diffraction light intensity.

关 键 词：离子导体 导电参数 

分 类 号：O482.4[理学—固体物理]