Strategy for optimizing piezoelectric properties of (1−x)Pb(In1/2Nb1/2)O3−0.05Pb(Mg1/3Nb2/3)O3−xPbTiO3 ceramics for medical applications

Abstract

Enhanced temperature stability and dielectric permittivity of piezoelectric materials are desirable for ultrasound-based transducer applications because the self-heating of devices during operation degrades piezoelectric properties and electrical impedance mismatching limits power transfer. To address these issues, (1−x)Pb(In_1/2Nb_1/2)O₃−0.05Pb(Mg_1/3Nb_2/3)O₃−xPbTiO₃ ceramics near the morphotropic phase boundary were synthesized using solid-state reaction method. These compositions exhibited mixed rhombohedral and tetragonal perovskite structures, and the tetragonal phase fraction increased with increasing x. The ε_r of the rhombohedral phase decreased, while that of the tetragonal phase increased after application of an AC electric field, and the tetragonal phase contributed more to d₃₃ than the rhombohedral phase. The rhombohedral phase gradually depolarized with increasing annealing temperature. The ε_r can be enhanced by utilizing the advantage of the depolarized rhombohedral phase without significantly sacrificing piezoelectric properties. This method has potential as a strategy to alleviate electrical impedance mismatching, enhancing the imaging performance of transducers for ultrasound-based medical diagnosis.