Grain size effect on piezoelectric properties of rhombohedral lead zirconate titanate ceramics

Lead zirconate titanate (PZT)-based piezoelectric ceramics are important functional materials for various electromechanical applications due to their excellent performance and temperature stability. Herein, the rhombohedral PbZr0.55Ti0.45O3 ceramics with increasing average grain size from 3.57 μm to 10.85 μm were prepared by a conventional solid-state reaction method. The grain-size dependent dielectric, ferroelectric and piezoelectric properties were systematically investigated. With the increasing grain size, a significant softening effect with enhanced electromechanical properties was observed. Results of piezoresponse force microscopy show that the formation of non-180° domain walls was strongly repressed in the fine-grain samples, resulting in decreased domain wall mobility. Meanwhile, a noteworthy hardening effect was also observed in the coarse-grain samples with high domain wall mobility, which may be related to the enhanced bulk effect with increasing grain size. The results of this work confirmed that grain size engineering is an effective strategy for designing piezoelectric materials with excellent combination properties.