Enhanced Exchange in the Itinerant Ferromagnet UFe2

Neutron inelastic scattering experiments on the itinerant ferromagnet UFe2 have shown that the strong hybridization between the U 5f and Fe3d electrons results in a number of major changes compared to the physics of the isotructural RFe2 (R=Tb, Ho, and Er) compounds. We have observed that the Fe-Fe exchange interaction in this compound is actually greater at low temperature than it is in pure iron. This situation is not found in the RFe2 compounds. Excitations involving the U moments are heavily damped. We conclude with remarks on the possibility of synthesizing compounds with high Curie temperatures containing uranium.JRC.E-Institute for Transuranium Elements (Karlsruhe