DISTRIBUTION OF RELAXATION-TIMES IN PEROVSKITE-TYPE RELAXOR FERROELECTRICS

The distribution of relaxation times in perovskite-type relaxer ferroelectrics is studied by computer simulation. It has been proved that the spectra move to longer relaxation times with the decreasing of temperature and the increasing of the external field. The frequency dispersion of relaxors is explained by a gradual freezing process of polar microregions. The relationship between the time dependence of the polarization and the relaxation time distribution at various temperatures and external fields has been investigated. The macroscopic polarization is suggested to be sustained mainly by frozen dipoles during the observation time. (C) 1995 American Institute of Physics.