An investigation was made of the surface atomic structure of silicide layers which had been grown epitaxially onto (111)Si. Two possible positions of the Si vacancy with respect to the terminal Si layer were considered. In one case, the vacancy was in the Si graphite-like plane that was located below a Si atom of the outermost or inner planes of the buckled Si top layer. The use of polarization-dependent photo-emission experiments, combined with electronic band-structure calculations and symmetry considerations, permitted the inner configuration to be ruled out.

A.Mharchi, L.Stauffer, S.Saintenoy, C.Pirri, P.Wetzel, D.Bolmont, G.Gewinner: Solid State Communications, 1996, 97[3], 249-54