Abstract
In order to investigate the electronic structures in the magnetically ordered states of CeSb, we measured the optical reflectivity and the magnetic circular dichroism in the infrared region at low temperatures under a magnetic field. The optical conductivity spectrum, as well as the reflectivity spectrum, varies with the changing of temperature and magnetic field due to the magnetic phase transition. The optical spectrum originates from the absorption from the top of the Sb 5 p band to the bottom of the Ce 5 d band. The spectra in the ordered states cannot be explained only by the energy band folding due to the appearance of the periodic magnetic structure. It was found that the Sb 5 p band is strongly modified by the appearance of the Ce 4 f Γ 8 state in the ordered state. The Sb 5 p-Ce 4 f mixing effect is considered to play an important role in the magnetic phase transition.
