Abstract
Optical and magneto-optical properties of a single crystal of metallic ferrimagnet Fe7Se8 grown by Bridgmann technique have been measured. This material crystallizes in hexagonal NiAs structure with a superstructure associated with the ordering of vacant Fe sites. Spectra of normal incidence reflectivity and polar magneto-optical Kerr effect were measured at room temperature. From these spectra diagonal and off-diagonal elements of conductivity tensor were evaluated. The results do not clearly show a contribution of intraband transition to the magneto-optical effect, but suggest a contribution of a band-to-band transition starting just below 0.5 eV. This implies the existence of a spin-orbit coupled band with large density of states just below the Fermi-level as supposed from its magnetic properties.
