LIQUID-LIKE MODEL FOR THERMAL-CONDUCTIVITY IN SUPERIONIC CONDUCTORS

Based on the assumption that the mechanism of energy dissipation in both superionic conductors and liquids are similar in a microscopic scale, a new model for the thermal conductivity in superionic conductors is presented. We use the theoretical results of Rice and Allnatt for dense fluids to describe the expression of thermal conductivity. The cage sublattice is considered through the introduction of a heavy-ion mass, which characterizes immobile lattice ions as a matter of convenience when we look at the system from the viewpoint of the liquid theory. We applied the model to -AgI to get a good agreement with the experiment. According to our model the main mechanism which is effective to thermal conduction is the hard-core collision between the mobile ions and the surrounding lattice ions. © 1990 The American Physical Society.