Realizing large strain at low electric field in Pb(Zr,Ti)O-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, large strains at low electric fields have not been well solved. Herein, 0.95Pb(Zr0.56Ti0.44)O3- 0.05(Bi0.5Na0.5)TiO3-xBaZrO3 (PZT-BNT-xBZ) ceramics with efficient ferroelectric domain wall motion were designed and realized by reducing lattice distortion and changing the domain structure. It is found that the introduction of BaZrO3 (BZ) weakens the tetragonal phase distortion of PZT, contributing to a reduction in the mechanical stress that impedes the migration of domain walls. Moreover, the domain structures could be modified by adjusting the 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 excellent temperature stability over the temperature range of 30-210°C. This study delves into the synergistic effects of reducing lattice distortion and changing domain structure on domain wall motion and provides an effective strategy to improve the strain of PZT-based piezoelectric ceramics.