XAFS IN THE HIGH-ENERGY REGION

XAFS (X-ray absorption fine-structure) spectra were measured near K-ab sorption edges of Ce (40.5 keV), Dy (53.8 keV), Ta (67.4 keV and Pt (7 8.4 keV). The blunt K-edge jump due to the finite lifetime of the core hole was observed. This makes it difficult to extract EXAFS (extended X-ray absorption fine-structure) functions at low k values. Local str ucture parameters can be evaluated from the EXAFS spectra above K-abso rption edges in the high-energy region as well as from those above L-I II-edges. It was found that the finite-lifetime effect of the core hol e is effectively taken into the photoelectron mean-free-path term, as predicted theoretically.