Propagation of surface acoustic waves across the randomly rough surface of an anisotropic elastic medium

Abstract

The propagation of surface acoustic waves across the randomly rough surface of an anisotropic solid is studied. In the small roughness limit the dispersion relation for such waves is derived. The frequency dependences of the dispersion and attenuation of surface acoustic waves are obtained for the case when the wavelength λ is long compared to the transverse correlation length a of the roughness. In this limit the numerical curves for the relative change of the phase velocity of surface acoustic waves versus the angle of propagation are calculated for the various cuts of anisotropic media. Crystals of cubic, tetragonal, trigonal, hexagonal, and orthorhombic symmetry, adopted in applications, are considered. The effects of piezoelectricity are taken into account through the approach of ‘‘partially stiffened elastic constants.’’