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, d(33); high voltage coefficient, g(33); high electromechanical coupling factor, k) and hard properties (high mechanical quality factor, Q(m); low dielectric loss, tan delta) along with wide operation temperature (e.g., high rhombohedral-tetragonal phase transition temperature Tr-t) for covering off-resonance (figure of merit (FOM), d(33) x g(33)) and on-resonance (FOM, Q(m) x k(2)) 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, textured 2 mol% MnO2 doped 0.19PIN-0.445PSN-0.365PT ceramics exhibiting giant FOM values of Q(m) x k(31)(2) (227-261) along with high d(33) x g(33) (28-35 x 10(-12) m(2) N-1), low tan delta (0.3-0.39%) and high Tr-t of 140-190 degrees 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.