A modified nucleation and growth model for ferroelectric switching in Form I poly(vinylidene fluoride).
01 January 1986
The analytical description of transient switching characteristics of Form I poly(vinylidene fluoride), PVDF, has so far been confined to the narrow time range where the switching current displays a modest peak under an applied dc field. We show here that this range can be broadened to encompass the entire switching process by considering the process to be composed of two successive events, the first involving only the nucleation of microdomains and the second entailing the random nucleation and two-dimensional growth. The model has been successfully applied to data obtained at temperatures between 20 and -80C from samples that had been either unirradiated or irradiated with gamma-rays (10 Mrad). Furthermore, our analysis revealed that the irradiation, which enhances the retention characteristics of piezoelectric property at elevated temperatures, primarily affects the main switching process by suppressing its rate of nucleation.