Surface vibrational properties

Abstract

An overview is given of the principal types of surface vibrational modes that occur at a clean surface of a solid and the means whereby they can be studied experimentally. The modes that are discussed include long-wavelength surface acoustic modes (Rayleigh waves), short-wavelength surface acoustic modes, long-wavelength surface optical modes (surface polaritons), and short-wavelength surface optical modes. Typical dispersion curves illustrating the various types of modes are presented. Mention is also made of surface vibrational modes associated with adsorbed species on solid surfaces. Experimental techniques that are discussed include inelastic electron and helium atom scattering, Raman and Brillouin scattering, acoustic wave reflection, and attenuated total reflection. Other vibrational properties considered are surface specific heat and surface mean square displacements (Debye–Waller factor).