X-RAY-ABSORPTION NEAR-EDGE STRUCTURE (XANES) STUDIES OF AU0.5AG0.5 - IMPLICATION FOR CHARGE REDISTRIBUTION AT BOTH AU AND AG SITES UPON ALLOYING

L-edge x-ray absorption near edge structure (XANES) has been used to study electronic structure of the titled alloy. It is found that (a) relative to pure Au, the alloy Au L2,3 edge XANES exhibits an increase in absorption coefficient just above the edge, indicating d-charge depletion at the Au site; (b) relative to pure Ag, the intensity of the alloy Ag L2,3-edge ''whiteline'' of the alloy decreases indicating d-charge gain at the Ag site; (c) these observations are accompanied by an increase in the Ag L1-edge ''whiteline'' intensity, a sign for the depletion of p charge. These results are discussed in terms of a charge compensation model.