Ultrahigh strain in PZ-PT-BNT piezoelectric ceramic

Low strain limits the further application of Pb(Zr,Ti)O3 (PZT) piezoelectric ceramics in actuators. Herein, a ternary piezoelectric ceramic xPbTiO3-(0.95-x)PbZrO3-0.05(Bi0.5Na0.5)TiO3 (xPT-PZ-BNT) is proposed and prepared by solid-state method to improve the strain characteristics. Results indicate that a biased electric field is intentionally constructed by defects arising from the incorporation of BNT into PZ-PT ceramic, which promotes non-180° domains to restore to initial states, thereby contributing to the increase in strain. Moreover, the electric domain configuration is efficiently modified by adjusting the component proportion in xPT-PZ-BNT ceramics, in which the 0.42 PT-PZ-BNT presents short and broad domains with fast response to external electric field. Rayleigh analysis indicates that the strain contributed by domain switching is dominant in PT-PZ-BNT ceramics under a high electric field. Consequently, a large strain of 0.4% is achieved in 0.42 PT-PZ-BNT ceramic with the variation less than 10% in the temperature range of 25∼175 °C. This study not only deeply analyzes the effect of domain configuration on the strain for PZT piezoelectric ceramics, but also demonstrates an effective approach to increase the strain through constructing internal biased electric field and regulating domain configuration.