Ferroelectric properties of the PbZrO3-PbTiO3 system

The dielectric and piezoelectric properties of solid solutions with compositions PbZr1-xTixO3, 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 (epsilon(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 mu 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.