Effects of spin-dependent spectral weight on magnetic circular x-ray dichroism: Applications to R(NixCo1−x)5 intermetallic compounds

This systematic study of R(NixCo1−x)5 compounds (R=La, Gd, and Tb) has allowed us to investigate the combined effects of the 3d-5d hybridization and 4f-5d exchange on the rare-earth L2,3-edge magnetic circular x-ray dichroism (MCXD) signal. In La compounds, where the 5d polarization results only from the magnetic transition metals via the hybridization of 5d and 3d bands, the MCXD signal scales with the 5d moment and can be explained by a one-particle model for the absorption process. When the 4f-5d exchange intervenes, like in the Gd and Tb compounds, its effects on the MCXD sign, amplitude, and the amplitude variations are very important. A description of the L2,3-edge MCXD spectra taking into account the spin-dependence of the radial matrix elements explains qualitatively the results of this study.Peer reviewe