INVESTIGATION OF THE ELECTRONIC-STRUCTURE IN CU-AU-I USING X-RAY-PHOTOELECTRON SPECTROSCOPY

We report x-ray-photoemission measurements on Cu-Au I and show that details of the valence-band spectrum are in agreement with recently published band-structure calculations. We find that upon alloying, the binding energy of the Au 4f core level increases by 0.30 +/- 0.05 eV and that of the Cu 2p3/2 core level decreases by 0.27 +/- 0.05 eV. We suggest that the tetragonal distortion is related to increased ionicity in the Cu-Au bonds. Characterization studies indicate that Au segregates to the surface of a polycrystalline sample.