X-ray magnetic circular dichroism at the U M(4,5) absorption edges of UFe2

We present an x-ray magnetic circular dichroism study performed at the U M(4,5) edges on UFe2, a ferromagnet with almost itinerant 5f electrons. The analysis of the branching ratio of the U M(4,5) edges confirms the fact that the occupation number of the 5f states in UFe2 is lower than in other compounds where the f electrons are more localized. Magnetic circular dichroism effects are observed consistently with the presence of an orbital 5f magnetic moment which aligns parallel to the total magnetic moment. In agreement with a polarized neutron study, we find a nearly perfect cancellation of the U-5f spin and orbital magnetic moments, which results in a vanishing small total U-5f magnetic moment. Results are discussed in comparison with atomic multiplet calculations.