J. Phys. IV France 7 (1997) C2-447-C2-448
Effects of Spin-Dependent Spectral Weight on Magnetic Circular X-Ray Dichroism: Application to R(NixCo1-x)5 Intermetallic CompoundsR. M. Galéra1, S. Pizzini1, 0, J.A. Blanco2, J.P. Rueff1, A. Fontaine1, Ch. Giorgetti3, F. Baudelet3, E. Dartyge3 and M.F. Lopez3
1 Laboratoire de Magnétisme Louis Néel Laboratory associated with the Université Joseph Fourier de Grenoble., CNRS, BP. 166X, 38042 Grenoble cedex 9, France
2 Dermanent address : Dpto. de Fisica, Universidad de Oviedo, 33006 Oviedo, Spain.
3 LURE, bâtiment 209d, Centre Universitaire Paris-Sud, 91405 Orsay cedex, France
Systematic study of the RE(NixCo1-x)5 compounds (RE=La, Gd and Tb) has allowed to investigate the combined effects of the 3d-5d hybridization and 4f-5d exchange on the RE L2,3-edge MCXD signal. In La(NixCo1-x)5 compounds, where the Sd polarization results only from the hybridization between the 5d and 3d bands, the MCXD signal scales with the Sd moment and can be explained by a one-particle model for the absorption process [1-3]. When only the 4f-5d exchange intervenes, like in the GdNi5 and TbNi5 compounds, its effects on the MCXD sign and amplitude are very important, they are understood in term of spin-dependence of the radial matrix elements. When both the 3d-5d hybridization and the 4f-5d exchange are present like in the Tb(NixCo1-x)5 compounds, the amplitude variations of the L2,3-edge MCXD spectra may be qualitatively descripted by a balanced contribution of both effects.
© EDP Sciences 1997