Monte Carlo studies of ionic conductors containing an insulating second phase
Abstract The ionic conductivity in solid ionic conductors containing a dispersed insulating phase (like LiI/Al 2 O 3 ) is studied within percolation theory. We develop a realistic three dimensional model which takes into account both the blocking of the mobile ions by the insulator and the enhanced conductivity along the internal interfaces. We calculate the overall conductivity by Monte Carlo simulations and find that the distinct conduction properties of the composites are explained satisfactorily by our model. In addition, we predict that dispersed ionic conductors should show critical behaviour of both random-superconducting and random-resistor networks near two different concentrations of the insulator, features which might be experimentally observable.