Optical and magneto-optical investigation on electronic structure of ordered ferromagnetic Fe3Pt

The optical and magneto-optical properties of ordered Fe3Pt have been investigated by spectroscopic ellipsometry and magneto-optical Kerr spectroscopy. The diagonal component of the optical conductivity tensor of the compound exhibits a broad absorption peak at about 2 eV, which is shifted by about 0.5 eV to lower energies from the corresponding one in pure bcc Fe. The Kerr angle spectrum of the compound disperses quite similarly in both spectral trend and magnitude to that of pure Fe below 3.5 eV but differently above it. The lower-energy shift of the 2-eV-absorption structure of the compound is interpreted as due to the shift of the minority-spin Fe-d states toward EF through the hybridization with Pt-d states. The Kerr effect of the compound is attributable to a large spin-orbit coupling in Pt as well as the well-hybridized spin-polarized bands.