Surface acoustic wave attenuation by a thin film

The attenuation of Rayleigh‐type waves traveling in a layered film‐substrate combination is calculated by including a loss term due to viscous damping in the equation of motion for the film. The attenuation can thus be readily obtained without heuristic arguments by an analytic continuation of the analysis for the velocity of a surface wave without damping. Comparison to previous models is made for various film and substrate materials.