Sublifetime-resolution Ag L3-edge XANES studies of Ag-Au alloys

High-resolution Ag L-3-edge XANES for a series of Au-Ag alloys, AuAg3, AuAg, and Au3Ag, have been obtained by monitoring the intensity of the highly energy-resolved Ag L3M4,5M4,5((1)G(4)) Auger line.:The experimental results reveal features that were previously unresolved with total electron yield techniques and confirm previous observations that Ag gains d charge and Au loses d in Au-Ag alloys. Full-scale multiple scattering calculations for the Ag L-3-edge XANES of Ag and AuAg yield semiquantitative agreement with the experiment. The results show that in the case of wide band metals, the Auger yield of a well-separated narrow final state can indeed be used to improve the resolution of XANES pear the threshold. The implication of the results to electron charge redistribution upon alloying is discussed.