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

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(In1/ 2Nb1/2)O3- 0.05Pb(Mg1/3Nb2/3)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 epsilon 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 epsilon 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.