STUDY OF POLING BEHAVIOR OF BIAXIALLY STRETCHED POLY(VINYLIDENE FLUORIDE) FILMS USING THE CONSTANT-CURRENT CORONA TRIODE

This article reports systematic results of corona poling measurements obtained on biaxially stretched polyvinylidene fluoride films charged in dry air. Charging was performed using the constant current corona t riode. The dependence of the poling process on the sample thickness, c harging current, and successive charging processes was investigated. P hase transitions from alpha to delta and to beta phases were observed when virgin samples were corona charged. The thermal pulse technique s howed that the polarization profiles during charging can be made consi stently almost uniform and that the ferroelectric reorientation can be associated with the rising plateau region displayed on potential buil dup curves. (C) 1995 American Institute of Physics.