X-ray magnetic circular dichroism in iron chalcogenides Fe1−xS: First-principles calculations

Abstract

The electronic structure of iron chalcogenides Fe1−xS (x=0 and 0.125) were investigated theoretically from first principles, using the fully relativistic Dirac linear-muffin-tin-orbital band structure method within the local spin-density approximation. At ambient conditions, stoichiometric FeS in the troilite crystal structure orders antiferromagnetically below the Neel temperature TN=598 K in an insulating ground state. The different models of antiferromagnetic ordering in FeS are analyzed and discussed. Densities of valence states, orbital and spin magnetic moments as well as x-ray magnetic circular dichroism (XMCD) spectra of Fe7S8 at the Fe K, L2,3, and S K edges are investigated. The origin of the structure in the XMCD spectra is examined. The calculated results are compared with available experimental data.