Fabrication and dielectric properties of Ba(Fe0.5Nb0.5)O3/poly(vinylidene fluoride) composites

To combine good dielectric properties and flexibility in high dielectric constant composite materials, the Ba(Fe0.5Nb0.5)O3 (BFN) particles with giant dielectric constant were dispersed in poly(vinylidene fluoride) (PVDF) polymer matrix. The Ba(Fe0.5Nb0.5)O3 powders were prepared via the conventional solid-state reaction route. The Ba(Fe0.5Nb0.5)O3/poly(vinylidene fluoride) composites were obtained by a physical mixing and a cold press technique. The structure, morphology and dielectric properties have been characterized and discussed in detail. The dielectric constants of the composites increase with the volume fractions of the BFN filler increasing from 20% up to 60% at all frequency (100 Hz–1 MHz). The BFN/PVDF composite with 60 vol% BFN shows the highest dielectric constant (ε′ ~57) at 100 Hz at room temperature. The value of dielectric constant of the BFN/PVDF with composite 60 vol% BFN is nearly six times as high as that of pure PVDF, which can be attributed to the interfacial polarization between the BFN and PVDF polymer matrix. It is believed that the Ba(Fe0.5Nb0.5)O3/poly(vinylidene fluoride) composites with high dielectric constant would be applied in the embedded capacitor field.