XPS-studies of the electronic structure of Fe-X (X=Al, Si, P, Ge, Sn) systems

For the stoichiometric compounds FeSi, FeGe, FeSn, FeAl, and FeP the X-ray photoelectron spectra of valence bands are obtained and the calculations of their electronic structure are carried out by the full-potential linear muffin-tin-orbital method (FP-LMTO) and by the tight-binding linear muffin-tin-orbital atomic sphere-approximation method (TB-LMTO-ASA). A satisfactory agreement of the X-ray photoelectron spectra and the calculated density of states curves is obtained. The comparison of the experimental spectra with the calculated curves shows that if the second component (X) of an alloy belongs to the same (IVth) group of the periodic table, the p-d hybridization is maximum in the alloy FeSi and decreased with the increase in the atomic radius (atomic number) of X(Ge, Sn). If X belongs to the same (IIIrd) row of the periodic table, then the p-d hybridization is maximum in FeAl and decreased with the increase in the number of p electrons of X(Si, P). (C) 2001 Elsevier Science B.V. All rights reserved.