Surface-core-level shift and valence-band studies of the Dy c(2 × 2) structure on W(1 0 0)

Using synchrotron radiation, ultraviolet photoemission spectroscopy technique has been used to investigate the electronic structure of dysprosium and W(1 0 0) under formation of a Dy c(2 × 2) structure. Valence-band photoemission studies indicated hybridization between Dy and W states. This study also showed a shift to higher binding energies in the Dy 4f level relative to the as-grown and Dy c(8 × 2) films. Core-level shift (CLS) analysis of the W 4f7/2 line-shape after formation of a c(2 × 2) structure showed three additional features in the W 4f7/2. The intensities of the components suggest that the feature with a CLS of 0.29 ± 0.02 eV relative to bulk feature (rtbf), is from the W sub-surface layer, the feature with CLS of 0.52 ± 0.02 eV (rtbf) is from the W surface with Dy atoms at hollow sites, and the feature with CLS of 0.62 ± 0.02 eV (rtbf) is from the bridge sites.