Europhys. Lett, 33 (1), pp. 35-40 (1996)
Surface and interface cerium electronic configurationin Ce/Fe (100)
B. Kierren , F. Bertran , T. Gourieux , D. Malterre and G. Krill
Laboratoire de Physique du Solide, Université H. Poincaré
BP239 54506 Vandoeuvre, France
Laboratoire pour l'Utilisation du Rayonnement Electromagnétique
Univerisité de Paris-Sud, F-91405 Orsay, France
(received 24 July 1995; accepted in final form 17 November 1995)
PACS. 71.28+d - Narrow-band systems; heavy-fermion solids; intermediate-valence
PACS. 79.60Bm - Clean metal, semiconductor, and insulator surfaces.
PACS. 73.20At - Surface states, band structure, electron density of states.
Abstract:The cerium electronic configuration of very thin films deposited on Fe(100) has been studied by core level photoemission. In the low-coverage regime ( monolayer), cerium atoms are in a trivalent state ( configuration). For larger coverages, cerium atoms exhibit a mixed valent state. This behaviour reflects the valence change of covered cerium atoms at the interface and results from the increase in the hybridization strength for these interface atoms. Owing to an original method, we were able to directly decompose our experimental spectra in two contributions corresponding to the covered ("bulk") and non-covered (surface) atoms.
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