Moessbauer Investigation of the Itinerant Magnets U(Ga0.98Sn0.02)3 and CeFe2

The theoretical predictions that UGa3 and CeFe2 should be regarded as itinerant magnets stimulated new investigations. In this paper we focus on Moessbauer measurements aimed to characterize their magnetic properties. We show that the analysis of the transferred hyperfine interactions at the 119Sn nuclei in U(Ga0.98Sn0.02)3, a type II antiferromagnet, provides direct information on the f-p hybridization and allows to determine the orientation of the U moments. The study of CeFe2 demonstrates that the intrinsic ferromagnetism coexists with short range antiferromagnetic correlations. The instability of the ferromagnetic state is illustrated by doping CeFe2 with a small amount of Co and by application of pressure on pure CeFe2. Our results will be discussed in connection with neutron and synchrotron experiments