Multiferroic PVDF-Fe3O4 hybrid films with reduced graphene oxide and ZnO nanofillers

Flexible and self-standing polyvinylidene fluoride (PVDF) films loaded with nanofillers, reduced graphene oxide (RGO), zinc oxide (ZnO) and magnetic iron oxide (Fe3O4) nanoparticles, were prepared by a solvent casting method. The crystallinity, morphology and structure of these films were studied using XRD, SEM, FTIR and Raman spectroscopy. FTIR studies reveal a higher percentage of polar ferroelectric beta-phase (similar to 80%) in both pristine PVDF and PVDF-RGO films, whereas the addition of nanofillers, Fe3O4 and ZnO, resulted in a reduced amount of beta-phase (similar to 50%) in the films. Of all the films studied, PVDF-RGO shows an enhanced dielectric constant as well as maximum electric polarization. On the other hand, Fe3O4 loaded-PVDF composite films exhibit reduced values of both dielectric constant and electric polarization. A weak magneto-dielectric behavior is observed in Fe3O4 loaded PVDF nanocomposite films at room temperature with a coupling constant similar to 0.04%.