Prediction of piezoelectric properties of crystal-ceramic composites

In the framework of the model of a piezoelectrically active ferroelectric crystal-ceramic composite of the 0–3 type, the concentration dependences of the effective piezoelectric properties of this composite are determined. Two examples of such composites are discussed: the single-domain PbTiO₃ crystal (Pb_{1 ? x}Ca _itx)TiO₃ ceramic and the polydomain PbTiO₃ crystal (Pb_{1 ? x}Ca_x)TiO₃ ceramic. Based on these examples, we analyzed the effect of the 90° domain structure, the form of crystalline inclusions, the remanent polarization of the ceramics, molar Ca concentration (x), and other factors of the effective piezoelectric coefficients e _3j ^* and d _3j ^* and and their anisotropy. The relation between the piezoelectric polarization of the composite to single-domain inclusions and the anisotropy of its piezoelectric coefficients is also studied.