Maxwell-Wagner relaxation in piezoactive media

Maxwell-Wagner piezoelectric, dielectric and elastic relaxations in two-layer or multilayer serial piezoactive media are considered. As distinct from the oversimple model, described in literature, we derive exact solutions by taking into account mechanical boundary conditions, transversal piezoelectric response and elastic properties of layers. We first study the Maxwell-Wagner relaxation of elastic compliances and the contribution from piezoelectric coefficients and elastic constants of two layers to the value of the relaxation time. Methods for strengthening as well as eliminating the relaxations and for the giant enhancement of dielectric permittivity are specially reviewed.