Ferroelectric Properties of the PbZrO3–PbTiO3 System

Abstract

The dielectric and piezoelectric properties of solid solutions with compositions PbZr 1- x Ti x O 3, x=0.200 to 0.750, with an 0.005Nb 2 O 5 additive prepared by modern ceramic technology were investigated, focusing on the morphotropic phase boundary (MPB, x=0.467). Relationships between the dielectric, piezoelectric and crystal phases were compared with results reported by Jaffe et al.. The relative permittivity (ε r) at room temperature increased in the composition range 0.465<x<0.480, corresponding to the MPB. The remanent polarization (P r) increased and the coercive field (E c) decreased in the rhombohedral phase approaching the MPB from the PZ side. The values were 41.1 µ C/cm 2 and 687.5 V/mm, respectively, at x=0.460. Also, as the PT content increased, E c increased on the tetragonal side of the MPB (x>0.469), resulting in a low P r. Large electromechanical coupling factors of k p=0.690 at x=0.465, k t=0.534 at x=0.470, k 31=0.415 at x=0.465 and k 33=0.71 at x=0.465 were obtained extremely near the MPB composition. These values were higher than those obtained by Jaffe et al.. Also, the frequency constant (F c) had a minimum value of 1901 Hz·m at x=0.465.