An analysis of shear horizontal surface acoustic wave propagation under mechanical losses

In piezoelectric materials, two kinds of losses can be distinguished: mechanical and dielectric. The loss effects are introduced in the Christofell formalism via complex elastic and dielectric coefficients, to evaluate the piezoelectric properties of shear horizontal surface acoustic waves. The surface permittivity concept is used to express the influences of losses on phase velocity, and the electromechanical coupling coefficient of the piezoelectric materials. The feasibility of this method is demonstrated with ZnO and AlN piezoelectric substrates.