5f-hybridization in URhAl studied by X-ray magnetic circular dichroism

We report X-ray magnetic circular dichroism experiments performed at the U-M-4.5 edges of an URhAl single crystal. Thanks to the sum rules, we derive an orbital magnetic moment on the uranium atoms equal to (1.63+/-0.14)mu(B). The comparison of the shape of the M-5 dichroic signal with pure J multiplet calculations shows effects due to 5f-hybridization. However, we found that the contribution of the magnetic dipole term [T-Z] to the effective spin moment [S-Z(eff)] = [S-Z] + 3[T-Z] is non negligible. These results indicate an higher localization of the 5f-orbitals with respect to other itinerant ferromagnetic actinides compounds such as UFe2 or UNi2. (C) 1998 Published by Elsevier Science S.A.