Ca-silicides as prototypical systems for modelling the electron-states at the Si(111)/Yb interface: a Si- L2,3 Auger lineshape investigation

The valence electron states at the Si(111)(2• 1)/Yb interface are discussed in terms of the Si L2,3VV Auger lineshape. The existence of Si 3p/Yb 5d interaction is inferred on the basis ofstrong similarities observed between the Si L2,3VV lineshapes of the interface reaction products and those of Ca silicides. Detailed spectroscopic assignments in the distribution of the valencestates are made possible by comparing the experimental spectra to theoretical calculations performed within the LMTO-ASA scheme.