Light-scattering study of the mercury liquid-vapor interface

High frequency capillary waves at a surface of mercury have been studied by means of quasielastic light-scattering spectroscopy. The observed damping constants of waves differ greatly from those predicted by the classical theoretical treatment of a Hg surface as that of a simple liquid. This effect is explained in terms of the presence of a surface layer of highly correlated atoms accompanying the Hg liquid-vapor transition. Viscoelastic properties of this layer are extracted from the fit of experimental spectra with a theoretical form utilizing a well known phenomenological model. The main conclusion of the present analysis is that the widely used hydrodynamic limit should be replaced by another form incorporating the Maxwell viscoelastic model.