Electronic properties of metal-rich Au-Si compounds and interfaces

A theoretical analysis of the electron density of states in the delta -phase Au3Si compound is given and the main aspects of the hybridisation between Si p and gold d orbitals are discussed. Differences in the electronic behaviour of Au-Si compounds with respect to those produced by nearly noble metals are pointed out. The theoretical results are compared with new photoemission data, which have been taken with synchrotron radiation using photon energy at the Cooper minimum, in order to distinguish the orbital contribution to the main structures. The general features of the experimental results agree with the theoretical model. A description of the main aspects of the chemical bond at the interface between Si and noble metals is provided.