Structural and functional properties of screen-printed PZT–PVDF-TrFE composites

Thick films of 0–3 composites of lead–zirconate–titanate (PZT) particulate and polyvinylidene-trifluoroethylene (PVDF-TrFE) copolymer have been produced by screen-printing on indium–tin-oxide (ITO)-coated glass substrates. The microstructure was investigated using scanning electron microscopy and X-ray diffraction. The dependences of the dielectric properties of the composites on PZT volume fraction are reported and analyzed in terms of an analytical model. The pyroelectric properties were determined using dynamical experimental setups, and are given in terms of pyroelectric coefficient and figures of merit. The piezoelectric response was investigated as a function of the PZT volume fraction using a laser vibrometer. The piezoelectric charge coefficient, d33,eff, is shown to exhibit a minimum at a PZT volume fraction of 40% which arises from the piezoelectric charge coefficients of the pure constituents being of opposite sign. It is thought that screen-printing of these composites constitutes a cost-effective way of producing structured functional thin films for pyroelectric and piezoelectric applications.