Water Quenched and Acceptor-Doped Textured Piezoelectric Ceramics for Off-Resonance and On-Resonance Devices

Piezoelectric materials should simultaneously possess the soft properties (high piezoelectric coefficient, d₃₃ ; high voltage coefficient, g₃₃ ; high electromechanical coupling factor, k) and hard properties (high mechanical quality factor, Q_m ; low dielectric loss, tan δ) along with wide operation temperature (e.g., high rhombohedral-tetragonal phase transition temperature T_r-t ) for covering off-resonance (figure of merit (FOM), d₃₃  × g₃₃ ) and on-resonance (FOM, Q_m  × k² ) applications. However, achieving hard and soft piezoelectric properties simultaneously along with high transition temperature is quite challenging since these properties are inversely related to each other. Here, through a synergistic design strategy of combining composition/phase selection, crystallographic texturing, defect engineering, and water quenching technique, <001> textured 2 mol% MnO₂ doped 0.19PIN-0.445PSN-0.365PT ceramics exhibiting giant FOM values of Q_m  × $$ (227-261) along with high d₃₃  × g₃₃ (28-35 × 10^-12 m² N^-1 ), low tan δ (0.3-0.39%) and high T_r-t of 140-190 °C, which is far beyond the performance of the state-of-the-art piezoelectric materials, are fabricated. Further, a novel water quenching (WQ) room temperature poling technique, which results in enhanced piezoelectricity of textured MnO₂ doped PIN-PSN-PT ceramics, is reported. Based upon the experiments and phase-field modeling, the enhanced piezoelectricity is explained in terms of the quenching-induced rhombohedral phase formation. These findings will have tremendous impact on development of high performance off-resonance and on-resonance piezoelectric devices with high stability.