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 P_y, the piezoelectric coefficients d_p, d₃₁ and e₃₁, and the dielectric response is investigated for poling fields up to E_p = 2.75×10⁶ V/cm. These quantities exhibit a plateau region where the initial rapid increase with increasing E_p 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 d_p and P_y for draw ratios up to 6:1 is also examined. d_p increases from 6.5 to 19 pC/N as the draw ratio goes from 1:1 to 6:1 (at constant E_p). P_y increases from 1×10⁻⁹ to 5×10⁻⁹ C/cm² K.