Realizing large strain at low electric field in Pb(Zr,Ti)O₃-based piezoelectric ceramics via engineering lattice distortion and domain structure

Pb(Zr, Ti)O₃-based ceramics are the mainstream materials for commercial multilayer piezoelectric ceramic actuators, but to date, it has not been well solved for achieving large strains at low electric fields. Herein, a 0.95Pb(Zr_0.56Ti_0.44)O₃-0.05(Bi_0.5Na_0.5)TiO₃-xBaZrO₃ (PZT-BNT-xBZ) ceramic with efficient ferroelectric domain wall motion was designed and realized by reducing lattice distortion and changing domain structure. It is found that the introduction of BZ weakens the tetragonal phase distortion of PZT, contributing to the reduction in the mechanical stress that impedes the migration of domain walls. Moreover, the domain structures could be modified by adjusting BZ content, where short and broad striped domains are constructed with high amplitude characteristics to enhance the domain wall motion. A large strain of 0.39% is accordingly achieved at an electric field as low as 40 kV/cm for the sample with x = 0.03, accompanied by an excellent temperature stability over the temperature range of 30 ^oC to 210 ^oC. This study delves into the synergistic effects of reducing lattice distortion and changing domain structure on the domain wall motion, and provides an effective strategy to improve the strain of PZT-based piezoelectric ceramic.