J. Phys. IV France 7 (1997) C2-1189-C2-1190
Ce Valence State Probed by XAFS Study in Ce2Fe17-xGaxMy Compounds (M = Light Interstitial Element)O. Isnard1, S. Miraglia1, P. Wolfers1, G. Krill2 and D. Fruchart1
1 Laboratoire de Cristallographie, CNRS, BP. 166X, Université J. Fourier, 38042 Grenoble, France
2 Laboratoire LURE, Bât. 209D, Université Paris Sud, 91405 Orsay, France
In the Ce2Fel7 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 Synchrotron radiation facility at LURE. We have studied the influence of interstitial element insertion on one hand and/or iron substitution by Ga on the other hand on the Ce L3 absorption edge. The results of XAFS are discussed in the light of neutron diffraction experiments that yield the interstitial element location and the substitution scheme in the local environment. This study shows that the large macroscopic magnetic change induces a significant evolution of the Ce L3 absorption edge. A partial relocalization of the 4f states is observed.
© EDP Sciences 1997