Energetics, structural and magnetic ordering of H/Fe/M(001), (M=Cu, Ag) systems

Abstract We performed density functional theory calculations using the full-potential linearized augmented plane wave method and generalized gradient approximation to investigate the interaction of hydrogen with Fe surface layers in the Fe/M(0 0 1) system, where M=Cu, Ag. The adsorption of hydrogen is found to be preferable at bridge sites in both H/Fe(0 0 1) and H/Fe/Ag(0 0 1), whereas the preferred sites are the fourfold site above the surface layer in the H/Fe/Cu(0 0 1) system. The adsorption energies are enhanced due to Cu and Ag substrates as compared to Fe(0 0 1) substrates. The local density of states at the Fermi level and the magnetic moments are reduced due to the presence of H for the different systems.