STRUCTURE AND DYNAMICS OF AN AG OVERLAYER ON CU(100) - A STUDY USING THE EMBEDDED-ATOM METHOD

We present the results obtained from molecular dynamics simulations of an overlayer of Ag on Cu(100) using potentials from the embedded atom method. As in the case of an Ag overlayer on Ni(100), the overlayer slides back and forth on the substrate along the nearly incommensurate direction. The mean square vibrational amplitudes of the Ag atoms are also largest along this direction. The Goldstone mode has a frequency of 1.3 cm-1 at 300 K. At higher temperatures the surface disorders and Ag and Cu atoms interdiffuse. The dispersion of the lowest frequency vertical mode is in good agreement with inelastic electron scattering data. We also present some explanations of the phonons at GAMMABAR and the structure factor of the system.