Analysis of the Electric Potential of an Acoustic Surface Wave Propagating on a Layered Half Space

For the case of a piezoelectric film on a nonpiezoelectric substrate, the electrical potential associated with a Rayleigh wave is expressed in terms of the stress field partial waves. Poisson's equation is solved with the stress field partial waves considered as source terms. The contribution from each term of the piezoelectric strain matrix to the total electric potential is found and examined. Numerical results are presented for the case of a (ZX) ZnO film on a fused silica substrate. The phase relationship between the longi- tudinal and shear terms is shown to account for the presence or absence of the second peak of coupling.