ADSORPTION OF AU ON RU(001) - ELECTRONIC PERTURBATIONS AND THE NATUREOF THE BIMETALLIC BOND

The electronic properties of Au/Ru(001) surfaces have been investigate d using high-resolution photoemission spectroscopy with synchrotron ra diation, and ab initio self-consistent-field calculations. For submono layer coverages of Au, the interaction between the Au 5d and Ru 4d ban ds produces an interface state that appears at similar to 1.5 eV. A mo nolayer of Au in contact with Ru(001) has a Au 4f(7/2) binding energy of similar to 0.25 eV higher than that of the surface atoms of Au(111) . The Au-Ru bond is complex with Au losing 5d electrons and gaining 6s and 6p electrons. This redistribution of charge affects the stability of the bimetallic bond.