Dielectric Relaxational Phenomena in Interacting Composite Structures

Dielectric relaxational properties of single systems, as well as in series and in parallel connected composite systems, as well as embedded structures, are simulated. The dielectric systems are modeled as randomly distributed and interacting permanent dipoles in 3-dimensional space between two parallel plate electrodes. The dipoles exist in double well potential structures and fluctuate due to thermal activation between two equilibrium positions, separated by a distance R and a barrier height W0. The method of images is employed to calculate the microscopic local fields at every dipole. In this way, all the depolarizing fields and interface effects are considered inherently. They are crucial in determining the macroscopic dielectric composite properties. A Monte-Carlo simulation technique iteratively calculates the transient polarizations in the time domain. A Fourier transform yields the frequency domain. The numerical results are compared to experiments using hafnium and aluminium oxides.