ELECTRON-SPECTROSCOPY STUDY OF THE 4F-ENERGY SHIFT AT THE SURFACE OF SAMARIUM METAL

The final states produced by the emission of a 4f electron from divalent surface atoms of Samarium metal are directly observed by varying the surface sensitivity of X-Ray Photoemission Spectroscopy (XPS). The minimum energy required to promote an electron from the Fermi level to the first unoccupied 4f state of trivalent bulk atoms is determined by Bremsstrahlung Isochromat Spectroscopy (BIS). The sizable energies involved in these transitions seem to make an intermediate valence at the surface very unlikely. © 1979.