Surface phonon dispersion ofc(2×2) S on Ni(100)

Abstract
The dispersion of the adsorbate- and substrate-associated modes of the Ni(100) surface covered with a c(2×2) sulfur overlayer has been measured along the Γ¯–X¯ direction by inelastic electron scattering. Experimental data are compared to a lattice dynamical model using an analytical Green’s-function technique. The optimum fit is obtained when the sulfur atom is placed at 1.45 Å above the nickel layer.