Dielectric and Pyroelectric Properties of (Pb_0.50Sr_0.50)TiO₃ Ceramics

Lead strontium titanate (Pb_0.50Sr_0.50)TiO₃ (PST) ceramics are prepared by the traditional ceramic processing. The dielectric constants and dielectric loss have been investigated in a temperature range from 25°C to 300°C. The maximum dielectric constants for unpoled and poled samples are 9924 and 9683, respectively. The temperatures of phase transition for unpoled and poled samples are observed at 153°C and 157°C, respectively. The phase-transition temperatures for unpoled and poled samples are not equal, which results from the polarization state of the domains. The remnant polarization and the coercive electric field are 18μC/cm² and 6kV/cm, respectively, from polarization-electric field (P-E) hysteresis loop. The temperature dependence of pyroelectric coefficients of the PST ceramics is measured by a dynamic technique. The dielectric constant and loss tan δ of the poled PST ceramics are 813 and 0.010, respectively. The pyroelectric coefficients and figure of merit are 294μC/cm²K and 13.6×10^-6Pa^-0.5, respectively, at room
temperature 25°C and frequency 100Hz.