Hybridization effects and magnetism in UPdSn

We report on the dependence of the interatomic distances in the intermetallic compound UPdSn as determined from the neutron diffraction data done on HIPD at Los Alamos spallation neutron source. The U-U distance gives a measure of the direct 5$f$-5$f $overlap. The U-Pd and U-Sn distances give a measure of 5$f$-ligand hybridization. Using the Rietveld refinement method, we were able to determine the interatomic distances in the range 15K-300K. The interatomic distances are found to decrease with decreasing temperature until the compound exhibits antiferromagnetic order around 40K. A second transition occurs around 25K.