The Eu valence state and valence transition in Eu(Pd1-xPtx)(2)Si-2

We examine the temperature dependence of the Eu valence and lattice paramet ers for Eu(Pd1-xPtx)(2)Si-2 by means of x-ray absorption spectroscopy (XAS) and x-ray diffraction, respectively. strong temperature dependence of the Eu valence was observed fur Eu(Pd1-xPtx)(2)Si-2. Combining the Mossbauer ef fect data and XAS results, we estimated the Eu valence as a function of tem perature. It is shown that the Eu valence in the ground state shows very li ttle sensitivity to x for 0 less than or equal to x less than or equal to 0 .10. In the temperature dependence of the Eu valence, the compound with x = 0.05 undergoes a continuous valence change, while the one with x = 0.15 sh ows a first-order valence transition. The factors determining the Eu valenc e in Eu(Pd1-xPtx)(2)Si-2 are discussed.