Effect of dielectrophoretic structuring on piezoelectric and pyroelectric properties of lead titanate-epoxy composites

Functional granular composites of lead titanate particles in an epoxy matrix prepared by dielectrophoresis show enhanced dielectric, piezoelectric and pyroelectric properties compared to 0–3 composites for different ceramic volume content from 10% to 50%. Two structuring parameters, the interparticle distance and the percentage of 1–3 connectivity are used based on the Bowen model and the mixed connectivity model respectively. The degree of structuring calculated according to both models correlate well with the increase in piezoelectric and pyroelectric sensitivities of the composites. Higher sensitivity of the electroactive properties are observed at higher ceramic volume fractions. The effect of electrical conductivity of the matrix on the pyroelectric responsivity of the composites has been demonstrated to be a key parameter in governing the pyroelectric properties of the composites. (paper)