Dielectric and piezoelectric properties of polymer piezoelectric 3-0 composites

The mixture rules of dielectric constants of biphasic polymer-piezoelectric composites with 3-0 connectivity have been modified by taking into account the local field interactions. The solution of Laplace equation for the scalar potential inside and outside the piezoelectric sphere dispersed in polymer matrix is obtained by using the proper boundary conditions. Using the local electric field obtained from the potential, an expression for the dielectric constant of the composite is obtained. An approach is developed by which, using modified mixture rules, the piezoelectric constants of composites can be estimated. The developed expressions are functions of dielectric, elastic, piezoelectric constants and volume fractions of constituent phases and compare very favourably with the available experimental data.