Spin-Resolved Spectroscopy and Magnetic Dichroism of Intermetallic Ferromagnets

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We investigated the electronic states of the ferromagnetic intermetallic compounds using high-energy spectroscopy. Magnetic information as local spin and orbital moment on magnetic and non-moagnetic atoms were yielded using circularly polarized incident light and by performing spin-analysis.MCD in Fe 2p XAS and Nd 3d and 4d XAS were taken for Nd_2Fe_<14>B.MCD in Fe 2p XAS shows that <Lz>/<Sz> of the 3d electrons is estimated to be as large as about 0.1. Comparison between experiments and calculations of MCD in Nd 3d and 4d XAS shows that the 4f electrons of Nd have a very atomic character.A very anomalous MCD line shape is found for CoPt_3, which is semi-quantitatively explained using a cluster-model incorporated with Fano effect. This analysis shows that <Lz>/<Sz> of Pt 5d electron is about 0.6. This work demonstrated for the first time that the orbital moment can be estimated by analysing the MCD even if a stron Fano effect is present.MCD in Co 2p XAS in CoS_2 shows that <Lz>/<Sz> of Co 3d electrons is about 0.2, in spite of the low-spin character of the Co 3d electrons. This can be reproduced qualitatlively by a calculation of the initial state using a cluster model taking into account the multiplet splitting due to the electrostatic interaction between the 3d electrons. Through this analysis, the origin of the orbital moment is shown to be the interplay between the non-diagonal element of the electrostatic interaction and the spin-orbit interaction. On the other hand, small but clear MCD was found for S 3p XAS.The origin is considered to be the exchange splitting of the S 3d partial density of state due to the hybridization with the Co 3d electrons.