Electronic structure investigation of Mg_1-xFe_xS solid solution: X-ray absorption study

X-ray absorption fine structure at the sulfur K edge in Mg_1-xFe_xS solid solution (0 ≤ x ≤ 0.68) has been measured at the Canadian Synchrotron Radiation Facility. It was shown that the S K-edge in MgS was formed by the multiple scattering of the photoelectron wave within a cluster of large size (containing 27 atoms and having radius about 4.5 Å). Comparison of experimental data with theoretical results allows study of the electronic structure of this system. The analysis of partial electronic density of s-, p- and d-states makes it possible to investigate the mutual influence of sulfur s-, p- and metal d- states in the conduction band. The study of changes in experimental S K-edges XANES of Mg_1-xFe_xS solid solution with variation of relative Fe-Mg concentration allows the extraction of the hypothetical cubic phase (B1) of FeS, and this is supported by theoretical simulation.