Defect engineering for reduced large AC signal dielectric loss of PZT‐based hard piezoelectric ceramics

Abstract

AbstractA low dielectric loss value under large AC electric fields is highly desired for piezoelectric ceramics in high‐power applications. However, only a few reports have focused on studying or revealing the dielectric loss behavior and mechanism of piezoelectric ceramics under an AC electric field. In this work, x (Ca, Fe) co‐doped Pb0.96Sr0.04Zr0.53Ti0.47O3 (x = 0.0, 0.25, 0.5, 1.0, 1.5 mol.%) hard piezoelectric ceramics (PSZT‐xCF) were selected for investigation. The lowest dielectric loss (@ E = 500 V mm−1) was 0.8% at x = 1.5 mol.% after aging for 30 days, which was a decrease by an order of magnitude compared with the counterpart pure PSZT. The origin of ultra‐low dielectric loss was thoroughly analyzed. Combined with Rayleigh's law, we investigated the reason behind the changes in dielectric permittivity under AC electric fields with aging time. The significant reduction in the contribution of extrinsic effect of domain wall motion dominated the reduction in dielectric loss because of the introduction of defect dipoles. This work provides a fundamental understanding of low dielectric loss piezoelectric ceramics under AC electric fields for high‐power applications.