Sm₂O₃-doped 0.28PIN-0.32PZN-(0.4-x)PZ-xPT piezoelectric ceramics with high Curie temperature and piezoelectric constant

In this work, Sm₂O₃-doped 0.28PIN-0.32PZN-(0.4-x)PZ-xPT (Sm-PbIZZT) ceramics were prepared by using the solid-state method. The microstructure and piezoelectric properties of Sm-PbIZZT were systematically analyzed. The results show that as the PT content increases, the content of the tetragonal phase gradually rises, and the Curie temperature goes up, while the dielectric constant and piezoelectric constant decrease. Cryogenic dielectric measurements, transmission electron microscopy (TEM), and piezoelectric force microscopy (PFM) analyses demonstrated that Sm₂O₃ doping combined with tuning MPB composition would introduce local structural heterogeneities and nanoscale domains. These changes, driven by internal and external synergistic effects, significantly enhanced the relaxor behavior and domain switching capability of material, leading to notable improvements in piezoelectric performance. It is revealed that 1 mol% Sm₂O₃-doped 0.23PIN-0.28PZN-0.13PZ-0.27PT ceramics exhibited the best piezoelectric performance, with a piezoelectric constant of 580 pC/N, an electromechanical coupling coefficient of 0.532, and a Curie temperature of 249°C, demonstrating exceptional piezoelectric performance combined with thermal stability. This research offers valuable insights into developing high-performance piezoelectric materials, highlighting their potential for high-temperature piezoelectric devices and energy harvesting applications.