CE VALENCE STATE PROBED BY XAFS STUDY IN CE2FE17-XGAXMY COMPOUNDS (M-EQUALS-LIGHT-INTERSTITIAL-ELEMENT)

In the Ce2Fe17 alloy, cerium is known to be in an intermediate valence state. The sensitivity of cerium electronic state to its environment has been probed by XAFS experiment on the XAS3 station of the DCI Sync hrotron radiation facility at LURE. We have studied the influence of i nterstitial element insertion on one hand and/or iron substitution by Ga on the other hand on the Ce L-3 absorption edge. The results of XAF S are discussed in the light of neutron diffraction experiments that y ield the interstitial element location and the subsitution scheme in t he local environment. this study shows that the large macroscopic magn etic change induces a significant evolution of the Ce L-3 absorption e dge. A partial relocalization of the 4f states is observed.