Thermal pulse study of the polarization distributions produced in polyvinylidene fluoride by corona poling at constant current Available to Purchase

A thermal pulse study of the polarization profiles in samples of 12‐μm‐thick, biaxially oriented polyvinylidene fluoride after corona poling under approximately constant‐current conditions, using a modified corona triode in atmospheric air, is reported. An electrical characterization of the corona triode is also reported to show how it may be operated in the constant‐current mode. Samples poled without electrode on the corona‐exposed surface show polarization distributions sensitive to the corona polarity, with polarization depletion on the corona side of the samples when the corona is positive. Polarization‐reversal experiments show switching inhomogeneities with a pronounced dependence on the initial corona polarity. The above observations are consistent with a simple model in which positive charges from the positive corona partially penetrate the sample during poling and cause an inhomogeneous reduction of the poling field.