Temperature Dependence of the Ferroelectric Properties of PLZT 6/58/42 Ceramics with Sb2O5 Addition

For a simple chemical composition of PLZT 6/58/42 with 1wt% Sb2O5 addition, excellent dielectric and piezoelectric properties of epsilon(r) = 4770, tg = 2.4%, d(33) = 800 pC/N, k(p) = 0.70, Q(m) = 46, k(t) = 0.54 and T-m = 185 degrees C can be obtained. The temperature dependence of dielectric constant at different frequencies shows that the as-prepared samples are relaxor ferroelectrics. By measuring ferroelectric hysteresis loops at different temperature, it is found that T-f = 122 degrees C is an anomalous point. Above T-f, the remnant polarization P-r decreases rapidly and reaches to zero at T-d = 130 degrees C. The results suggest that T-f is a characteristic temperature indicating the formation of macro-domains with appreciable sizes.