SPECTROSCOPIC STUDIES OF SURFACE AND SUBSURFACE HYDROGEN METAL SYSTEMS

Recent experiments on the H/Ni(111) system have demonstrated that high-resolution electron-energy-loss spectra of subsurface absorbate species can be observed. We report here molecular-dynamics simulations for both the H/Ni(111) and H/Pd(111) systems. The necessary atomic forces are obtained from embedded atom method (EAM) potentials. From such calculations we have obtained the power spectra and compare our results to the available experimental data. These calculations reasonably reproduce the observed shifts upon embedding the H subsurface and we comment on the possibility of subsurface absorbates interfering with surface adsorbate assignments. Lastly, we illustrate the sensitivity of our results to the parametrization of the EAM potential.