VALENCE-BAND SPECTRA OF 4D AND 5D SILICIDES

A full study of the electronic structure of 4d and 5d silicides (RuSi, RhSi, PdSi, OsSi, IrSi, Ir3Si5, IrSi3, PtSi) is undertaken including XPS VB and XES (Si K beta(1,3) and Si L-2,L-3) measurements and LMTO b and structure calculations. It is found that d bands which dominate th e density of states are more localized with increasing atomic number Z of the transition metal. A strong hybridization between silicon 3p an d transition metal d states occurs over the entire valence band. Si 3s states are found to be not mixed with Si 3p and nd states but Si 3d s tates participate in bonding and hybridize with transition metal d sta tes. The non-bonding character of the majority of nd states is not con firmed for 4d and 5d silicides.