The application of piezoelectric ceramics in electronic device materials demand the properties of these materials to be resistant against the change of temperature. In the $Pb(Zr,Ti)O_3$ system, it has been reported that there was a close relation between physical anisotropy and temperature dependence of piezoelectric properties. The purpose of this study is to know the process of change in dielectric, piezoelectric and elastic anisotropies during poling and the temperature characteristics of piezoelectric properties from the view point of domain reorientaion.
In this study, $0.37Pb(Zn_{1/3}Nb_{2/3})O_3-xPbTiO_3-(0.63-x)PbZrO_3[0.37PZN-xPT-(0.63-x)PZ]$ ceramic system was selected for relatively low sintering temperature (1150℃, 1hr) and high piezoelectric properties($d_33=350×10^{-12}C/N$). The change of dielectric, elastic and piezoelectric properties with d.c field and temperature in 0.37PZN-xPT-(0.63-x)PZ ceramics was discussed from the view point of domain reorientation mechanism.
In the rhombohedral phase region, dielectric and elastic properties were saturated at relatively low electric field compared with those in the tetragonal phase region and also the change of these properties were saturated at different electric field in the tetragonal phase region. From the examination of X-ray diffraction patterns and the coercive field measurement, it is found that the change of dielectric and elastic properties in the tetragonal phase is affected with 180˚ domain clamping and 90˚ domain reorientation respectively.
From the measurement of thermal expansion and the change of high temperature X-ray diffraction patterns for rhombohedral and tetragonal phases, it is considered that more stable temperature characteristics of the tetragonal phase than that of rhombohedral one is originated from the stable temperature dependence of 90˚ domain reorientation for the poled tetragonal composition. The temperature dependence of dielectric properties is more influenced by 180˚ domain reversal from both tetragonal and rhombohedral phases.
