PHOTOEMISSION-STUDY OF CE/NI(110) SYSTEM

We have studied the electronic structures of Ce/Ni(110) system by the 4d-4f resonant photoemission using synchrotron radiation and the Ce3d core level X-ray photoemission. The results are interpreted in conjunction with the inter-diffusion of Ce and Ni atoms through the interface. The annealing after the deposition of Ce causes active diffusion of Ce atoms into the Ni substrate and Ni atoms into the Ce layers and brings about a well-ordered surface. Both the Ce3d core level and valence band spectra show remarkable changes depending on the degree of inter-diffusion between Ce and Ni at the interface. It is revealed that a close relation exists between the Ce concentration and strength of the 4f-conduction states hybridization in the surface layer. The importance of the Ce4f-Ni3d hybridization is emphasized.