5F-HYBRIDIZATION IN URHAL STUDIED BY X-RAY MAGNETIC CIRCULAR-DICHROISM

We report X-ray magnetic circular dichroism experiments performed at t he 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 signa l with pure J multiplet calculations shows effects due to 5f-hybridiza tion. However, we found that the contribution of the magnetic dipole t erm [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 5 f-orbitals with respect to other itinerant ferromagnetic actinides com pounds such as UFe2 or UNi2. (C) 1998 Published by Elsevier Science S. A.