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 were simulated by the Monte Carlo-finite element method on a three-dimensional lattice. Effective dielectric constants with coefficients of variation less than 5.5% were obtained for different ratios of dielectric constants of the two phases, ranging from 10 to 700. Various mixing rules and equations were fitted to these data and the accuracy and relevance of the fits were examined. The modified logarithmic rule lost its physical basis when fitted to three-dimensional data. As the ratio of dielectric constants of the two phases increased, the parameters in the general Lichterecker mixing rule, the general Bruggeman's symmetric equation, the general effective media equation and its modified form all increased or decreased monotonously. The general effective media equation and its modified form gave the best fits to the effective dielectric constants simulated. The simulation results for the dielectric constants of some composite systems were in good agreement with experimental data. 31 refs.