Synthesis and ferroelectric investigations of poly(vinylidene fluoride-co-hexafluoropropylene)-Mg(NO3)2 films

The free-standing, flexible, and ferroelectric films of poly(vinylidenefluoride-co-hexafluoropropylene) [P(VDF-HFP)] were prepared by spin coating method. The ferroelectric phase of the films was enhanced by adding magnesium nitrate Mg(NO3)2 in different wt % as the additive during the film fabrication. The effects on the structural, compositional, morphological, ferroelectric, dielectric, and leakage current behaviors of the films due to the addition of salt were analyzed. Based on the X-ray diffraction (XRD) patterns and Fourier Transform Infrared (FTIR) spectra, it is confirmed that the addition of Mg(NO3)2 promotes the electroactive β phase that induces the ferroelectric property. The fiber-like topography of the films exhibits a nodule-like structure, and the roughness of the films increases by the addition of Mg(NO3)2. The ferroelectric studies show the higher polarization values for the composite films than that of the plain P(VDF-HFP) film. The Piezo-response force microscope images also confirm the domain switching behavior of the samples. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44008. © 2016 Wiley Periodicals, Inc.