A numerical method for the calculation of dielectric nanocomposites

Numerical simulations of the properties of dielectric nanocomposites using local field calculations are performed. Thus the dipole-dipole interactions and interactions between the dipoles and the electrodes are considered. The simulations are based on the microscopic local field method and a dynamic Monte Carlo algorithm. In the context of dielectric binary mixtures no analytic solution exists for a given microstructure. Such a problem can only be solved numerically. The approximations for such a system using macroscopic mixing rules can be misleading. We compare the results obtained by the local field method to the classical mixing rules of Maxwell-Garnett and Polder-van Santen. In the context of a polar guest phase in a non-polar host phase the impact of the nanodielectric inclusion modeled by permanent dipoles into the host matrix is investigated. For a two phase system with polar and non-polar units we simulate all interactions and investigate the ferroelectric hysteresis. The ferroelectric hysteresis is observed for the modeled P(VDF/TrFE) structure with dielectric layers on both sides. We will see that many effects which are unique for a given microstructure can not be observed by the application of a strategy of homogenization which is the case for all empirical mixing rules.