Improved electromechanical properties of Pb(Ni_1/3Nb_2/3)O₃–PbZrO₃–PbTiO₃ ferroelectric ceramics via Sm-modification

Sm-modification has recently attracted widespread attention as an optimized method for enhancing the electromechanical properties of Pb-based perovskite ferroelectrics. The present study extends the application of Sm-modification to the Pb(Ni_1/3Nb_2/3)O₃–PbZrO₃–PbTiO₃ (PNN-PZT) ceramics, aiming to improve their electromechanical properties. The impact of Sm-doping on the phase structure, microstructure, domain morphology, dielectric and piezoelectric properties was comprehensively investigated. The results demonstrate that the Sm-doping enhances the dielectric and piezoelectric properties while retaining competitive ferroelectric-paraelectric phase transition temperature (T_m). Notably, for the 2 mol% Sm-doped samples, a significant piezoelectric coefficient d₃₃ of 1130 pC/N and a high T_m of 130 °C were achieved, accompanied by an improved dielectric constant (ε_r) and electromechanical coupling factor (k_p). The comprehensive properties of Sm-doped PNN-PZT ceramics exceed the general trend observed in current Pb-based ferroelectric ceramics. This research confirms the effectiveness of the Sm-modification method in PNN-PZT systems, establishing it as a promising candidate for high-performance electromechanical applications.