J. Phys. IV France 02 (1992) C2-145-C2-148
Model of polarization conductivity in ionically conducting glassesJ. C. GIUNTINI1, F. BUET1, F. HENN1, J. V. ZANCHETTA1 and J. VANDERSCHUEREN2
1 Université Montpellier II, Laboratoire de Physico-Chimie des Matériaux Solides, (URA D 407 CNRS), 34095 Montpellier Cedex 5, France
2 Université de Liège, Chimie Macromoléculaire et Chimie Physique, SART TILMAN, 4000 Liège, Belgium
We have used a hopping conduction model to calculate the frequency-dependent polarization conductivity, [MATH] in ionically conducting glasses, and we have assumed that a short-range ionic hopping mechanism occurs based on a fluctuation process. We have underlined the fundamental differences between the frequency-dependent polarization conductivity due to "bound-charge" and the dc conductivity related to "free-charge" diffusion. The law [MATH] is observed as for electronic charge-carriers in amorphous substances. The expression of parameter s is modified by the introduction of a term connected with the fluctuation probability. A plot of the function T/1-s = f(T) shows a striking difference in behaviour (slopes) between ionic glasses (Na2O-3SiO2, (Ag2S)x (GeS21-x) and electronic amorphous solids.
© EDP Sciences 1992