ELECTRONIC-STRUCTURES OF FES AND FES2 - X-RAY-ABSORPTION SPECTROSCOPYAND BAND-STRUCTURE CALCULATIONS

The band structures of FeS and FeS2 including the S 3s and 3p and the Fe 3d and 4s states are calculated in the tight-binding approach. In t he case of FeS, magnetic ordering is taken into account. The Fe K, Fe L(2,3), and S KX-ray absorption edges have been recorded and are discu ssed in terms of the calculated band structures. The three absorption edges and the corresponding partial density of states (PDOS) in the co nduction band are presented on a common relative energy scale for both compounds. This allows an interpretation of those structures in the s pectra which correspond to bands not accessible by the calculation (pa rticularly those derived from Fe 4p states). It is shown that the meth od of using band structure calculations together with a maximum number of absorption edges of a compound allows to describe conduction bands up to higher electronic levels and gives a detailed interpretation of X-ray absorption spectra. (C) 1997 Elsevier Science Ltd. All rights r eserved.