The x-ray absorption spectroscopy (XAS) concerns the study of electronic transitions from
inner shells to unoccupied states. Electronic and structural information on selected
absorbing sites can be obtained in complex systems just by tuning the x-ray energy of the
beam light impinging onto the sample. In this way the atomic species under study can be
selected and their environment explored (I). The absorption coefficient shows a more or less.
pronounced oscillatory structure as a function of the photon energy above the rising edge …