Electric poling effect on capacitance of ferroelectric polymer composites

In this paper, we report the electrate properties of ferroelectric polymer PVDF and its composites with three different fillers as ceramic-BaTiO3, metallic semiconductor-ZnO and metallic-TiO2 in PVDF matrix. Each type of PVDF composites thin films with 2wt%, 6wt% and 10wt% of fillers were synthesized by solution casting techniques using dimethylformamide (DMF) as solvent. The XRD pattern confirms the formation of tetragonal perovskite structure of ferroelectric retaining 13-phase and shows proper mixing of fillers interstitially and improved crystallinity with increase of composition in the PVDF matrix. Electric poling effect on the pristine PVDF and its composites were studied by measuring the relative change in strain capacitance using LCR meter. The PVDF and its composites have shown systematic oscillations in strain capacitance with applied electric field. The variation in the strain capacitance is explained in terms of dynamics of dipole pinning and electrostriction induced strain capacitance.