Temperature dependence of piezoelectric properties of a high Curie temperature Pb(In1/2Nb1/2)O-3-PbTiO3 binary system single crystal near a morphotropic phase boundary

The temperature dependence of the dielectric and piezoelectric properties o f a 0.72Pb(In1/2Nb1/2)O-3-0.28PbTiO(3) binary system single crystal oriente d along the [001] axis near a morphotropic phase boundary was investigated in poled and unpoled states. With poling, the permittivity epsilon (r) and the dielectric loss tangent tan delta decrease from 2650 and 0.05 before po ling to 800 and 0.01 after poling. respectively. The change in both the eps ilon (r) and the tan delta at the ferroelectric rhombohedral-to-tetragonal phase transition temperature Tf, with temperature are significantly reduced with poling. The electromechanical coupling coefficient in the rectangular bar mode, k'(33) = 77%, for phase-array ultrasonic transducers was obtaine d using the rhombohedral 0.72(In1/2Nb1/2)O-3-0.28PbTiO(3) single crystal or iented along the [001] axis. With increasing temperature, the value of k'(3 3) decreases slightly in the rhombohedral phase, shows a slight anomaly aro und Tf,, and then remains almost constant in the tetragonal phase. Even at 200 degreesC, the k'(33) value decreases by only 5%. The piezoelectric cons tant d(33) was 700 pC/N at room temperature.