Fabrication And Dielectric Properties Of The BaTiO₃/Polyvinylidene Fluoride Composite Thin Films With High Dielectric Permittimity

High dielectric constant polymer-based dielectric materials are very important in electrical engineering and micro-electronics fields. The composites consisting inorganic particles embedded in a polymer matrix have attracted more and more attentions due to the advantage that combine the facile processability and high breakdown field of the polymer with the high dielectric constant of ceramic fillers.In this work polyvinylidene fluoride (PVDF) with excellent dielectric properties is chosen as the matrix of the composites. Dielectric composite films of the micro-nanosize BaTiO3 (BT) particles embedded into a PVDF matrix were prepared by using a simple blending and casting processing. Effects of the micro-nanosize BT cofilled way on microstructure and dielectric properties of the composite films were researched. The results show that the dielectric properties and the breakdown field of the composite films with the micro-nanosize BT loading at 40 vol% is higher than these with single nanosize BT loading solely if the interactions between the BT fillers are considered. The maximum values of dielectric permittivity and breakdown field were about 55 and 136 MV/m respectively because of the superior internal microstructure of composite films. The microstructure and the assumed cofilled model of the composite films would used to explain the experimental results well.