Electronic properties of a pseudomorphic Cu-layer on Ni(111)

Abstract

The band structure of a monolayer Cu on Ni(111) was studied both by angle resolved UV photoemission spectroscopy (ARUPS) and density functional (DF) calculations. The Cu 3d-bands at binding energies between 2 eV and 5 eV show a very pronounced k ‖ dispersion along the [11 2] and [ 110] substrate directions, but no dispersion with k ⊥. This proves the two-dimensional character of the Cu 3d-bands. The periodicity of the bands coincides with the periodicity of the Ni(111) surface. The experimentally determined two-dimensional band structure of the pseudomorphic Cu monolayer on Ni(111) is in very good agreement with the results of DF calculations on the system. From this comparison we obtain detailed information about the Cu/Ni interaction and the k-dependent coupling of Cu and Ni bands.