Pseudo binary alloys like R(A1-xBx)2 compounds are known to exhibit both negative and positive
types of deviation from Vegard's law on substitution of 3d or 4f cations. CeNi2 based alloys are known to be
mixed valence compounds whereas CeFe2 alloys are probably not. In this study we examine the influence of
substitution of rare earth compounds rather than the 3d ions. Ce LIII absorption edge XAFS is measured in
the single phase Ce1-xYxFe2 system (x = 0.0, 0.1, 0.2, 0.3 and 0.7) using the super ACO synchrotron
radiation facility at LURE. The spectra are discussed in terms of the change in the Ce valence as a result of
progressive substitution by trivalent Y cation. The problem of Ce valence saturation is also addressed in this
work. ?? 1995.
