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 Kβ1,3 and Si L2,3) measurements and LMTO band structure calculations. It is found that d bands which dominate the density of states are more localized with increasing atomic number Z of the transition metal. A strong hybridization between silicon 3p and 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 states participate in bonding and hybridize with transition metal d states. The non-bonding character of the majority of nd states is not confirmed for 4d and 5d silicides.