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

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-LiIO 3 single crystal was measured by this method. The results are as follows. The activation energy of mobility E μ =0.36eV. The formation energy of Frenkel defect E M =0.59 eV. At 300K, both the number densities of positive and negative carriers are 1.6×10 17 cm -3 ; their relative concentrations are 1.07×10 -5 ; the effective mobility μ eff + =3.9×10 -8 cm 2 ·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 μ eff - = 3.4 ×10 -9 cm 2 ·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.