A simulation model for dielectric relaxation based on defect diffusion model and waiting time problems

Abstract

We propose a simulation model for dielectric relaxation based on defect diffusion. The defect diffusion model (DDM) has been used to interpret dielectric relaxation and other relaxation phenomena. The essential feature of the model is a cooperative interaction between the relaxing dipole and its nearest-neighbors, containing defects, and the relaxation can only occur when a defect encounters a dipole. In our model we have taken the motion of defect as a stochastic process characterized by successive waiting time problem rather than classical random walk motion. We present computer simulation result for a simple dipolar model system and the dipole correlation function obtained from this new model under various physical conditions appears to be in the form of a stretched exponential function. (c) 2010 Elsevier B.V. All rights reserved.