Diffusional and vibrational properties of Cu(001)-c(2x2)-Pd surface alloys

Interatomic interaction potentials constructed in the framework of the embedded-atom method are used to study the structural, diffusional, and vibrational properties of ordered Cu(001)-c(2 x 2)-Pd surface and subsurface alloys. The equilibrium structures obtained for these alloys are in good agreement with experimental data and the results of other calculations. The calculated diffusional characteristics are consistent with the experimental kinetics and evolution of the surface alloys and attest to the stability of the subsurface alloy. The activation energy for planar diffusion of palladium in the initial stage of the alloy formation agrees with the value measured using scanning tunneling microscopy. The calculated surface phonon frequencies agree well with the experimental values obtained using electron-energy-loss spectroscopy. The results show that the Cu-Pd bond is strong and that the bond between surface copper atoms weakens. (C) 2005 Pleiades Publishing, Inc.