Well-balanced performance achieved in PZT piezoceramics via a multiscale regulation strategy

Emerging high-power piezoelectric applications demand the development of piezoelectric materials featuring both a high mechanical quality factor (Q_m) and a large piezoelectric coefficient (d₃₃). However, it is widely accepted that an increase in d₃₃ is usually accompanied with a decrease in Q_m, and vice versa. Herein, a multiscale regulation strategy is proposed to improve Q_m and d₃₃ simultaneously from the perspectives of phase structure, ferroelectric domains, and lattice defects. A well-balanced combination of electromechanical performances with Q_m = 726, d₃₃ = 502 pC N^-1, k_p = 0.69, tan δ = 0.0024, and T_C = 267 °C was obtained. Through structural characterization, it was observed that the morphotropic phase boundary and enhanced dispersion behavior lead to a lowered energy barrier, which contributes to polarization rotation and enhances piezoelectric performance. At the same time, the excellent piezoelectric performances also benefit from the highly oriented domain structure and small domain size after high-temperature poling. Furthermore, the segregation of Ba²⁺ causes A-site defects in the crystal lattice, accompanied with an increase in oxygen vacancies, which maintains the hardening effect of the ceramics. This study proposes a multiscale regulation strategy, providing insights for the design of high-power piezoelectric ceramics with high d₃₃ and Q_m.