Time-domain spectrum of dielectric relaxation in relaxor ferroelectrics : Monte Carlo simulation

We perform Monte Carlo simulation on the dielectric relaxation behaviour of a model relaxor ferroelectric, based on the Ginzburg-Landau theory of ferroelectrics with dipole-defect induced random field. The coexistence of ferroelectric nanoclusters and paraelectric matrix is demonstrated. It is found that the time-domain spectrum for dielectric relaxation below the ferroelectric transition point exhibits a multi-peaked pattern rather than the diffusive single-peaked pattern, indicating the existence of multi-characteristic times for the dielectric relaxation. The extended multi-peaked time-domain spectrum is responsible for the diffusive ferroelectric transitions and frequency dispersion of the dielectric relaxation, usually observed for relaxor ferroelectrics.Department of Applied Physic