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.