X-ray photoemission study of Pr/noble metals (Ag, Au) and Pr/transition metals (Ni, Pd)

Abstract The electronic properties of the interfaces ofPr/Ag, Au, Ni, and Pd were studied by X-ray photoemission spectroscopy. Pr thin films with coverage between 0.2 and 6.4 ML were prepared by evaporation onto the metal substrates at room temperature. Core level shifts of the substrates and Pr as well as changes of Pr 3d spectral shape were observed as a function of Pr coverage, indicating that the formation of intermixing alloys occurs at the interfaces. In Pr3d 5/2 spectra at low coverage, a high energy satellite with shoulder structure is interpreted as an f 1 final-state peak. This suggests that the tetravalent Pr state exists at very low Pr coverage.