5f Magnetism Studied in Complex Intermetallic U-based Hydrides

Hydrogen absorption in uranium ternary intermetallic compounds typically increases ordering temperatures and magnetic moments. The case of URuSn hydride, which does not behave accordingly, can be related to specific H positions revealed by neutron diffraction on deuterides. Tuning through the onset of magnetic ordering by means of H absorption was found for the U2T2X compounds as U2Co2Sn. For U2Ni2SnD1.8, we demonstrated that the anisotropic lattice expansion leads to U moments reorientation, as a result of hybridisation-induced two-ion anisotropy,with respect to U2Ni2Sn, in which the U U coordination is poised between two regimes.JRC.E.6-Actinides researc