Dielectric and functional properties of polymer matrix/ZnO/BaTiO3 hybrid composites

Ceramic–polymer composites incorporating ferroelectric and piezoelectric crystal particles, randomly distributed within the polymer matrix represent a novel class of materials. Composites including ferroelectric and/or piezoelectric particles are expected to exhibit functional properties because of the varying polarization of the ceramic particles. In the present study polymer matrix/ZnO/BaTiO3 composites were prepared, in different filler concentrations. The dielectric response of all samples was studied by means of broadband dielectric spectroscopy, over a wide temperature (from 30 °C to 160 °C) and frequency (from 10−1 Hz to 10 MHz) range. Experimental data were analyzed by means of dielectric permittivity and electric modulus formalisms. Dielectric permittivity and loss are increasing with ceramic filler and diminishing rapidly with frequency. The functionality of the composite systems is related to the abrupt variation of the real part of permittivity, in the vicinity of the characteristic Curie temperature of BaTiO3, and to the relaxing polarization of the ZnO particles.