Acoustic phonons at the (111) surface of chromium

Abstract
Recent Brillouin scattering data for the (111) surface of Cr (Sandercock 1978) are compared with the theoretical cross section computed for a semi-infinite anisotropic elastic medium undergoing free-surface boundary conditions. The surface ripple mechanism is found to be responsible for the continuum of phonon states localised between the transverse and longitudinal thresholds.