Micro- and nanosized effect of Ba(Fe0.5Nb0.5)O3 fillers on dielectric properties of Ba(Fe0.5Nb0.5)O3/PVDF composites

Polymer based composites with high dielectric permittivity and low dielectric loss are realized by employing giant dielectric permittivity Ba(Fe_0.5Nb_0.5)O₃ (BFN) powder as a functional inorganic filler and poly(vinylidene fluoride) (PVDF) as polymer matrix. Micro- and nanosized BFN powders were obtained via the conventional solid-state reaction method and the oxalate coprecipitation method, separately. The morphology and dielectric properties of micro-BFN/PVDF and nano-BFN/PVDF composites have been characterized and investigated comparatively. The nano-BFN/PVDF composites show much higher values of permittivity than micro-BFN/PVDF composites in all of concentrations, which is due to the more interfacial polarization effect causing by larger interfacial areas in the composites containing nanometer scale BFN fillers. At the same time, the dielectric loss of nano-BFN/PVDF composites is as low as that of micro-BFN/PVDF composites.