Abstract
Surface vibrations are investigated with a high resolution electron spectrometer (ΔE≈10 meV). For sufficiently low electron energies the electrons are scattered mainly by the extended electric dipole field associated with certain types of surface vibrations. The excitation of Fuchs-Kliewer surface modes in infrared-active materials is illustrated in zinc oxide. On the cleaved (111) silicon surface a surface phonon of ℏω=56 meV is found. Furthermore, the localized modes of oxygen adsorbed on a (111) silicon surface are discussed. The sensitivity of electron spectroscopy is several orders of magnitude higher than light spectroscopy.