X-ray absorption near edge structure of small FePt atomic clusters

X-ray absorption near edge structure of small FePt atomic clusters has been studied using a full multiple scattering, a self consistent field, and the real-space Green's function approach realized via the ab initio FEFF8.20 code. We show the M, difference spectra of the Pt L3 edge with respect to the size and shape of the small FePt atomic clusters. The difference spectra at the Fe L3 edge also shows variation, but is less pronounced as compared with the results from the Pt L3 edge. Calculations are made with and without core-hole. It is shown that the white line intensity is reduced for both the Pt and Fe L3 edges with the core-hole. In the case of Pt U edge the shape of the spectra without the core-hole agrees much more closely with the experimental results. (C) 2004 Published by Elsevier B.V.