On the existence of interfacial (Stoneley) waves in bonded piezoelectric half-spaces

A new definition of the piezoelectric limiting speed, based on the piezoelectrically stiffened acoustical tensor is introduced. The Stoneley wave problem is readily formulated for bonded piezoelectric half-spaces in both the Φ and F representations introduced by Lothe & Barnett. The notion of the F piezoelectric interfacial impedance tensor, which is an extension of the elastic interfacial impedance tensor, is used to show that a maximum of two subsonic Stoneley waves can occur. A definite existence criterion for a single subsonic piezoelectric Stoneley mode is given, and a numerical scheme that searches for Stoneley modes, when they exist for a given geometry and material combination, is also presented along with a numerical example for two joined cadmium sulphide half-spaces.