Dielectric, Ferroelectric, and Piezoelectric Investigation of Polymer‐Based P(VDF‐TrFE) Composites

In this study we report on the dielectric, ferroelectric, and piezoelectric properties of the conventional polyvinylidene fluoride/trifluoroethylene, P(VDF‐TrFE), copolymer of composition 70/30 mol.% with fillers on the basis of lead zirconate titanate (PZT). (Pb0.75Ba0.24Sr0.01)(Zr0.53Ti0.47)O3 (BPZT) fillers with concentrations from 10 to 50 vol.% are additional components in the P(VDF‐TrFE) piezoelectric polymer. Dielectric spectroscopy and the characterization of ferroelectricity and piezoelectricity in the P(VDF‐TrFE)/BPZT composites are performed over a wide temperature range from 150 to 420 K. The dependence of the effective dielectric permittivity for the composites under investigation on the filler concentration is analyzed by the Lichtenecker mixing rule. The approximation model of effective medium is also applied to explain the impact of BPZT fillers on the ferroelectric and piezoelectric properties of P(VDF‐TrFE)/BPZT composites. The proposed Lichtenecker's mixing rule can be applied to explain the passive behaviour of ceramic particles in the composites of P(VDF‐TrFE) polymer and barium‐doped lead zirconate titanate (BPZT). Also, the authors demonstrate the frequency dependence of the piezoelectric coefficients below room temperature, which presumably is related to the glass transition of the polymer matrix.