Effect of poling procedure on the properties of lead zirconate titanate vinylidene fluoride-trifluoroethylene composites

Lead zirconate titanate/vinylidene fluoride-trifluoroethylene [PZT/P(VDF-TrFE)] 0-3 composites for pyroelectric sensor and piezoelectric transducer applications have been fabricated by incorporating PZT powder into a P(VDF-TrFE) copolymer matrix. The properties of these composites can be tailored to suit designated applications by varying the ceramic volume fraction and by using different poling procedures. As both phases in the composite are ferroelectric, and the piezoelectric coefficients of the ceramic and copolymer phases have opposite signs while the pyroelectric coefficients have like signs, special ways can be used to produce three groups of samples with (1) only the ceramic phase poled, (2) two phases poled in the same direction to achieve reinforced pyroelectric activity and reduced piezoelectric activity, and (3) two phases poled in opposite directions to obtain reinforced piezoelectric activity and reduced pyroelectric activity. In this work, original experimental results on the properties of PZT/P(VDF-TrFE) composites poled under different conditions are presented and possible reasons behind the reinforcement and cancellation of piezoelectric and pyroelectric properties are discussed. (C) 1999 American Institute of Physics. [S0003-6951(99)01120-1].