Initial-State Shift of the Carbon2sLevels of Chemisorbed Hydrocarbons on Nickel

Abstract

Uv photoemission results using filtered $h\nu =40.8\mathrm{}$-eV radiation show strong shifts in the low-lying $\mathrm{C}\mathrm{}\left(2s\right)\mathrm{}$-derived levels of chemisorbed hydrocarbons on Ni relative to the higher-lying $\sigma$ levels. These differential shifts provide evidence for initial-state potential and/or rehybridization effects which are important in interpreting high-lying valence orbital shifts and the bonding of chemisorbed species.