Surface gap wave propagation in layered electro-magneto-elastic structures

Abstract

This paper considers the propagation of surface gap waves in two different layered structures, each of which consists of two half-spaces separated from each other by a small vacuum gap. In the first case the substrate is a piezoelectric material of crystal class 6, 4, 6 mm, 4 mm, 622 or 422, and the upper half-space is a dielectric medium. In the second case the substrate is superconducting and the upper half-space is a magnetic medium. The propagation of a surface shear electro-elastic wave in the first structure and a Rayleigh type magneto-elastic wave in the second structure is investigated. Dispersion equations are derived for both cases. For the first structure electro-mechanical coupling effects are investigated and the dependence of the solutions on the piezoelectric and dielectric parameters is found. For the second structure magneto-mechanical coupling effects are investigated, and a critical value of the magnetic field intensity is found at which surface waves no longer propagate.