Brillouin Scattering from Surface Phonons in Thin Films

Abstract
Brillouin scattering from thermal surface phonons has been observed in thin films deposited on semi-infinite media. The velocity of Rayleigh and Sezawa waves was measured and interpreted in terms of the film elastic constants. Surface phonon attenuations were also measured and it was found that the lifetimes of surface and bulk phonons of the same wave vector are comparable in the glass studied.