Excellent temperature stability of strain in PZ-PT-BNT ternary ceramics

Abstract

Lead-based Pb(Zr, Ti)O3 ceramics have been widely applied in piezoelectric actuators, and yet high temperature stability and large strain have been pursued for further application. In this work, a novel PbZrO3–PbTiO3-(Bi0.5Na0.5)TiO3 (PZ-PT-BNT) piezoelectric ceramic is designed and prepared by solid-state route. It is found that the introduction of BNT constituent enhances the relaxation behavior of PZ-PT ceramic, inhibits the abrupt change in dielectric properties near Curie temperature, and increases the proportion of tetragonal phase with high temperature stability. Meanwhile, the patterns of electric domains are intentionally modified by adjusting composition of PZ-PT-BNT. Short and broad electric domains in PZ-PT-0.03BNT ceramic are observed by piezoresponse force microscopy, which are insensitive to temperature and have faster response under electric field, contributing to strain characteristics. As a result, through integrating phase structure and electric domain configuration, a strain of 0.21% and excellent temperature stability where the variation of strain is less than 8% in the temperature range of 25–250 °C are achieved in PZ-PT-0.03BNT ceramic. The findings provide an effective strategy for improving the strain stability of PZ-PT-based piezoelectric ceramics, and demonstrate that PZ-PT-BNT ceramics have potential application prospects in high-temperature piezoelectric actuators.