Enhanced dielectric properties in poly(vinylidene fluoride) composites by nanosized Ba(Fe0.5Nb0.5)O3 powders

A composite with enhanced dielectric permittivity is realized by employing Ba(Fe0.5Nb0.5)O3 (BFN) with giant dielectric permittivity as a functional inorganic filler and poly(vinylidene fluoride) (PVDF) as a polymer matrix. The microstructures, thermal properties and dielectric properties of the nano-BFN/PVDF composites are discussed in detail. On account of the homogeneously distributed structure and inorganic nature of nano-BFN particles, the nano-BFN/PVDF composites show better thermal stability than that of the pure PVDF. The dielectric permittivity of the composites is as high as 93 when the concentration of the nanometer scale BFN fillers reaches 60 vol.% at 102 Hz. The maximum value of dielectric permittivity of nano-BFN/PVDF composites is 9 times higher than that of pure PVDF matrix, which is attributed to enhanced interfacial polarization. Among various theoretical models, the experimental permittivities of the BFN/PVDF composites match well with theoretical values by the Yamada models.