Evaluation of mixing rules for dielectric constants of composite dielectrics by MC-FEM calculation on 3D cubic lattice

Effective dielectric constants of diphase composite dielectrics are simulated by Monte Carlo-finite element method on three-dimensional lattice. Effective dielectric constants with coefficients of variation less than 5.5% are obtained for different ratios of dielectric constants of the two phases, ranging from 10 to 700. Various mixing rules and equations are fitted to these data and the accuracy and relevance of the fits are thoroughly examined. Modified logarithmic rule loses its physical basis when fitted to three-dimensional data. As the ratio of dielectric constants of the two phases increases, the parameters in general Lichterecker mixing rule, general Bruggeman's symmetric equation, general effective media equation and its modified form all increase or decrease monotonously. General effective media equation and its modified form give the best fits to the effective dielectric constants simulated. The simulation results for the dielectric constants of some composite systems are in good agreement with experimental data.