Dielectric behaviour of BaTiO3 / P (VDF-HFP) composite thin films prepared by solvent evaporation method

This work deals with the study of the molecular mobility as well as the evolution of the permittivity in P(VDF-HFP)/BaTiO₃ composites. The composite thin films of P(VDF-HFP) with BaTiO₃ (0%, 3.5% and 7.2% by v/v%) were prepared by solvent evaporation method. In addition a sample of 11.8% in volume fraction of X7R “temperature stable” formulations was prepared in order to compare the behaviour of both ceramics. In dielectric study, three relaxation processes are identified corresponding to the ß, αc and ionic relaxations in the temperature range -70 °C/130 °C. The incorporation of fillers does not modify the relaxations of P(VDF-HFP) copolymer, nevertheless fillers increase the permittivity of the composites in accordance with the theoretical model for organic/inorganic medium.