Optimizing electromechanical response and thermal endurance simultaneously via phase boundary engineering for high-power applications of PMS-PZT ceramics

In order to satisfy the demands of high-power applications, the desire to improve electromechanical properties of piezoelectric ceramics has become increasingly urgent. A conventional ternary ceramic system 0.05Pb(Mn_1/3Sb_2/3)O₃-xPbZrO₃-(0.95-x)PbTiO₃ (x = 0.45–0.49) (0.05PMS-xPZ-(0.95-x)PT) was studied through regulating the ratios of rhombohedral (R) and tetragonal (T) phases in this research. The phase compositions, microstructures, electromechanical properties and thermal stability of ceramics were characterized. The 0.05PMS-0.47PZ-0.48PT ceramics near the morphotropic phase boundary (MPB) reveals remarkable comprehensive properties (d₃₃ = 418 pC/N, Q_m = 1762, FOM = d₃₃* Q_m = 7.37 × 10⁵ pC/N, T_c = 331 °C, tanδ = 0.28% (at 25 °C), ε_r = 1606, k_p = 0.62). Compared with the undoped PMS-PZT research reported before, the FOM is improved by 57.5%. Additionally, it also exhibits excellent thermal stability that from 25 °C to 150 °C, the variation of d₃₃ is less than 5%. The outstanding comprehensive properties are primarily ascribed to the optimal ratio of the R and T phases which is 19/81 and the pinning effect of defect dipoles. The XPS and PFM result directly proved the presence of defect dipoles and exhibited the structures of domains. The strong “defect dipole-strain cooperative pinning” in T phase rich MPB yield high Q_m when the d₃₃ is enhanced at the same time. The results of this research especially the high FOM, low tanδ and excellent thermal stability indicate that the 0.05PMS-0.47PZ-0.48PT ceramics could be a promising alternative for the productions of piezoelectric devices working in a large temperature range in high-power fields.