Evolution of depolarization temperature of PLZT from normal to relaxor ferroelectrics

Abstract

Lead lanthanum zirconate titanate (PLZT x/59/41) ceramics with x from 0 to 6.5 mol. % are synthesized by the traditional solid-state reaction method. The temperature dependences of dielectric and resonant responses are used to characterize the depolarization processes of poled samples. It is found that the temperature of anti-resonance frequency minima (Tmin-a) accords completely with dielectric loss peak temperature (Tloss). The Tloss instead of anomalous dielectric peak temperature (Td*) can be regarded as depolarization temperature (Td). The Td* deviated from the Tloss suggests that the depolarization process in all the samples includes two stages: domain decoupling and polarization disorientation. With La content increasing, the Tloss decreases and the temperature difference ΔT between Tloss and dielectric peak temperature (Tm) increases nearly linearly. Since all studied samples have similar depolarization and freezing processes and the 0 mol. % La sample behaves like a normal ferroelectric, here we suggest that there may be no essential difference in depolarization process between relaxor and normal ferroelectrics.Lead lanthanum zirconate titanate (PLZT x/59/41) ceramics with x from 0 to 6.5 mol. % are synthesized by the traditional solid-state reaction method. The temperature dependences of dielectric and resonant responses are used to characterize the depolarization processes of poled samples. It is found that the temperature of anti-resonance frequency minima (Tmin-a) accords completely with dielectric loss peak temperature (Tloss). The Tloss instead of anomalous dielectric peak temperature (Td*) can be regarded as depolarization temperature (Td). The Td* deviated from the Tloss suggests that the depolarization process in all the samples includes two stages: domain decoupling and polarization disorientation. With La content increasing, the Tloss decreases and the temperature difference ΔT between Tloss and dielectric peak temperature (Tm) increases nearly linearly. Since all studied samples have similar depolarization and freezing processes and the 0 mol. % La sample behaves like a normal ferroelectric, here we ...