Rayleigh-Wave Electromechanical Coupling Constants

Abstract

The relative change in surface-acoustic-wave velocity, Δν/ν∞, caused by a thin conducting film on the surface, has been measured for several orientations of LiNbO3, quartz, LiTaO3, Bi12GeO20, and ZnO. This measurement was accomplished by monitoring the phase shift of surface-wave delay lines as an aluminum film was vacuum deposited onto the propagation path. Less than 100-Å-thick films completely short circuited the surface electric field. From the results, new more accurate values of surface-wave coupling constants are derived.