EXCITATION-SPECTRA OF INCOMMENSURATE LI CHAINS ON A CU(100) SURFACE

According to low energy electron diffraction (LEED) measurements, Li a toms form linear incommensurate chains in the missing rows induced by Li adsorption on a Cu(100) surface at room temperature and in the cove rage range from 0.375 to 0.4. The motions of these Li atoms in the cha ins are discussed by the classical molecular dynamics calculation. The vibrational excitation spectra of this system are also calculated. Li atoms are assumed to move not only parallel to the surface but also p erpendicular to the surface in the missing row by the periodic potenti al from the substrate Cu atoms. This situation is treated in an approx imate manner to show that the spectra obtained may be observed by spec troscopy measurements such as those made by high resolution electron e nergy loss spectroscopy.