Study of the L3 edges of ion-beam-mixed PdCu alloys by X-ray absorption spectroscopy

X-ray absorption spectroscopy (XAS) at the L3 edge of Pd is used to investigate the electronic structure of ion-beam-mixed PdCu alloys with a wide composition range (0.1≤x≤0.9). The formation of chemical bonds between Pd and Cu affects the occupancy and/or hybridization of the d states, and this change is revealed in the white line intensities. It is found that, within ion-beam-mixed PdCu alloys, there is a substantial decrease in the area of the Pd L3 white lines upon increasing the Cu concentration. This result implies that upon alloying with Cu there is a gradual filling of the Pd d band. The amount of d-charge transfer at the Pd site of ion-beam-mixed PdCu alloys has been estimated on the basis of the change within the white line.