Unoccupied states and charge transfer in Cu-Pd alloys studied by bremsstrahlung isochromat spectroscopy, x-ray photoelectron spectroscopy, and L(III) absorption spectroscopy

We have observed the unoccupied partial Pd 4d density of states in Cu-Pd alloys by bremsstrahlung isochromat spectroscopy (BIS). It shows the filling of the Pd 4d band upon alloying, which is consistent with the Pd L(III) absorption spectroscopy measurements. We have also determined the total charge transfer between Pd and Cu atoms from the binding energy shifts in the core-level x-ray photoelectron spectroscopy and the intensity of unoccupied Pd d states in the BIS spectra. This is compared with the result from the Pd L(III) absorption spectroscopy.