Spin-polarized and spin-integrated photoemission study of itinerant ferrimagnetic iron chalcogenides

Itinerant ferrimagnetic metals Fe7S8 and Fe7Se8 and antiferromagnetic semiconductor FeS have been studied by spin-polarized and spin-integrated photoemission and inverse-photoemission spectroscopy. Comparison with the density of states given by band-structure calculations indicates that the Fe 3d band is narrowed with spectral weight transfer towards higher binding energies and that the intensity at the Fermi level is suppressed. The band narrowing and the spectral weight transfer is reproduced by including the self-energy correction, suggesting the importance of electron correlation. Spin-polarized photoemission spectra of Fe7S8 and Fe7Se8 show negative spin-polarization near the Fermi level and spin-dependent correlation effect.