On the problem of the valence determination of Eu in mixed-valence compounds EuCu2Si2and EuPd2Si2

Abstract
The authors present a new analysis of the 151Eu Mossbauer spectra as a function of temperature (320-4.2K) for EuCu2Si2 and EuPd2Si2. Combining the Mossbauer effect results with complementary X-ray diffraction data and chemical analysis provides new information on the local valence behaviour in these compounds and clarifies the confusion that has existed in the past. It is shown that these new Mossbauer data should be considered in a reevaluation of the LIII X-ray absorption and magnetic susceptibility data, in which the details of the local Eu environment can not be resolved.