Dielectric and relaxation studies in hydrothermal processed PLZT ceramics

Abstract

(Pb_1-yLa_y)(Zr_0.52Ti_0.48)O₃ (PLZTy) powders were prepared using hydrothermal process and their structural and dielectric properties investigated. Increasing La content is shown to enhance crystallization of the raw samples and to transform the average symmetry to tetragonal one in the calcined ones. Two anomalies are observed on the real part of the permittivity on the sample with y = 0.03, at a relatively high temperatures (~ 180 °C, ~ 260 °C). The latter was interpreted as a transition from ferroelectric-rhombohedral phase to ferroelectric-quadratic phase. A quadratic law in temperature was used to study the temperature dependence of the dielectric constant of the samples showing the relaxation phenomenon and values of the fitting parameters such as the diffuseness parameter were calculated and discussed.