Band-Theoretical Description of the Magneto-Optical Spectra of UAsSe

The magneto-optical Kerr spectra of the ternary uranium compounds UAsSe are investigated using first-principles energy-band thoery. Within a band-like description of the 5f electrons, good agreement with the measured optical spectra is obtained. UAsSe is therefore the first uranium compound where density-functional theory in the local-density approximation satisfactorily explains the magneto-optical Kerr spectra. This is further evidence for at least partially itinerant 5f electrons in UAsSe, in spite of it frequently being cgaracterized as a localized 5f ekectron system. It is suggested that the 5f electrons are delocalized in planes perpendicular to the c-axis and that the magneto-optical Kerr spectra are extremely anisotropic.JRC.E-Institute for Transuranium Elements (Karlsruhe