Experimental determination of the R(5d)-T(3d) hybridization in rare-earth intermetallics

We present an x-ray magnetic circular dichroism XMCD study performed at the R L2 edge in RAl2 and RT2 T=Fe,Co intermetallic compounds. By analyzing the modification of the XMCD spectra as both the rare earth and the alloyed element Al, Fe, or Co are changed in the compound, an extra contribution, XMCDT, has been identified and undoubtedly associated with the R 5d -T 3d hybridization in Fe and Co compounds. The sign and intensity of this contribution are found to be related to the magnetism of the T neighboring atoms as well as to the strength of the T-R interaction. These findings open the possibility of experimentally quantifying both the R 4f -R 5d and the T 3d -R 5d hybridizations, which govern the R-T interaction.