We suggest that ionic conductors containing a dispersed insulating phase are suitable materials for investigating static and kinetic aspects of percolation. We develop a lattice model for the two-phase mixture with special emphasis on the role of an enhanced interface conductivity. By using two-dimensional Monte Carlo simulations we show that our model correctly describes the distinct conduction properties of those materials, and in addition displays the critical behavior of both random-superconducting and random-resistor networks at two different critical concentrations.

• Received 2 April 1985

DOI:https://doi.org/10.1103/PhysRevLett.55.5