The Dielectric and Piezoelectric Properties of the 1-3 Model PMN-PT/PVDF Composite Materials

We have prepared a group of 1-3 model Pb (Mg1/3Nb2/3) O3-PbTiO3/ polyvinylidene fluoride (PMN-PT/ PVDF) piezoelectric composite sheets using a hot-pressing method, which exhibits a high dielectric permittivity of 560 and low loss at 100Hz. Under low field, the electric-induced deformation of 0.075% is mainly attributed to the inverse piezoelectric predominated, and yet under above the coercive field, it is electrostrictive effect predominant that shows a butterfly-shaped strain curve and a maximum strain of 0.38%. Attractively, a very large piezoelectric coefficient of 1485 pC/N and a considerable electromechanical coupling factor of 0.68 are obtained in PMN-PT/PVDF sheet with a thickness of 2.1 mm, which is attributed to the horizontal compression activity that improves the radial strain effect. Consequently, the piezoelectric PVDF replacing nonpolar epoxy resin-based matrix and thereby constructing the 1-3 type composites are expected to have potential application prospects of matrix ultrasonic probes.