Study on dielectric behavior of a three-phase CF/(PVDF+BaTiO3) composite

A three-phase composite with a conductive carbon-fiber (CF) and ferroelectric phase (BaTiO3) embedded into polyvinylidene fluoride (PVDF) was prepared by using a simple blending and hot-molding technique. The dielectric properties of composites containing CF in (PVDF + BaTiO3) matrix as a function of the frequency and the volume fraction of CF were studied. The dielectric constant has a weak dependence on the frequency below 1 MHz and increases rapidly when the CF content is very close to the percolation threshold. The temperature has little effect on the variation of the dielectric constant. The percolation theory and the microstructure of the composites with CF are used to explain the experimental results. (C) 2003 Elsevier Science B.V. All rights reserved.