Structure-Dependent 4f -Core-Level Binding Energies for Surface Atoms on Ir(111), Ir(100)-(5×1), AND METASTABLE Ir(100)-(1×1)

Shifts in the core-level binding energies of surface atoms relative to bulk atoms which show a dramatic dependency on surface crystallography have been observed. Surface-atom core-level emission intensities are shown to give direct information on the number of surface atoms, while binding energies give information on the surface-atom coordination number. These data show that the reconstructed Ir(100)-(5×{}1) face is described by a compressed hexagonal monolayer.