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RESUME:Differents Qchantillons de CeO preparQs sous diverses conditions experimen-2 tales ont Qtb analysbs par photoabsorption X cmparativement au Ce m6tallique. Pour les Qchantillons sous stobchiomQtriques, les pics caractbristiques de Za valence ce3+ sont largement dominants. Pour le dioxide "pur" il n'y a pas dlQIQctrons 4f localisQs P 1'Qtat fondamental; des Btats Qtendus P caractsre 4f sont obser-v6s confirmant ainsi la covalence partielle de la liaison dans ce compos6 ABSTRACT:Various samples of CeO prepared under different experimental conditions have been studied by X-ray pho$oabsorption comparatively to Ce metal. For substoichiometric samples, peaks characteristic of the ce3+ ion are predominant. For"purel' dioxyde the spectra reveal no localized 4f states are present in the ground state while extended states with 4f character are observed confirming partial covalency of bonding in CeO 2 '