Antiferromagnetic ordering and 5<i>f</i>-electron localization in metallic PuPdSn

While the effect of electronic correlations is relatively well studied in Ce, Yb and U based materials, there is still lack of knowledge on how these collective phenomena impact magnetic, transport, and thermodynamic properties in transuranium intermetallics. Depending upon the strength of the interactions, many unusual properties such as complex magnetism, Kondo effect, heavy fermion ground state, valence fluctuations, and/or unconventional superconductivity have been observed in these materials. Here we present our detailed studies on the structural, magnetic, thermal, and transport properties of PuPdSn. This compound crystalizes in the hexagonal ZrNiAl-type of structure [space group P62m]. It orders antiferromagnetically at T_N = 21 K that is followed by another AF-like transition at 9.6 K. The low-temperature linear specific heat coefficient is small, γ∼8 mJ/mol K². All the results obtained strongly suggest the presence of well localized 5f-states in this material, which is rare among U and Pu intermetallics.

We are grateful to R. Jardin and J. Rebizant for sample preparation and characterization.