Magnetic linear dichroism in spin-resolved Fe 2p photoemission

Linear magnetic dichroism is studied for the Fe 2p level by angle- and spin-resolved photoemission with high energy resolution. The dichroism occurs in angle-resolved experiments for a geometry as in the transverse magneto-optic Kerr effect, i.e., on reversal of sample magnetization in the direction normal to the plane defined by light polarization and electron emission. The large spin-orbit splitting allows us to investigate the j=1/2 and j=3/2 states separately. Spin analysis allows differentiation between polarization effects related to exchange and spin-orbit interactions. The results are discussed in the framework of an atomic model, where the exchange interaction between the magnetic d shell and the core hole lifts the degeneracy of magnetic sublevels of the core hole spectrum. The model is able to explain the general trend in the spectra, but does not fully account for the observed shapes of the j=3/2 peaks. The analysis shows that the dichroism is governed by the spin polarization parameter which determines the spin-orbit-induced spin polarization. This shows that if there is a magnetic dichroism then there is a finite spin-orbit-induced spin polarization. The rich structures observed in our complete experiment are evidence for the influence of many-electron effects in the Fe 2p spectrum.