The poling field and draw dependence of the piezoelectric and pyroelectric response of pressure-quenched, phase I poly(vinylidene fluoride) films

Abstract

Recent investigations have shown that unoriented phase I poly(vinylidene fluoride) films can be produced by pressure quenching. The poling field dependence of the pyroelectric coefficient Py, the piezoelectric coefficients dp, d31 and e31, and the dielectric response is investigated for poling fields up to Ep = 2.75×106 V/cm. These quantities exhibit a plateau region where the initial rapid increase with increasing Ep decreases. This behavior is similar to that observed for unoriented and biaxially oriented phase II poly(vinylidene fluoride) films. The effect of draw ratio on dp and Py for draw ratios up to 6:1 is also examined. dp increases from 6.5 to 19 pC/N as the draw ratio goes from 1:1 to 6:1 (at constant Ep). Py increases from 1×10−9 to 5×10−9 C/cm2 K.