Crystal Structure and Physical Properties of NpPd2Sn

A new compound NpPd2Sn was prepared and studied by means of X-ray diffraction, magnetization, electrical resistivity and heat capacity measurements. Its crystal structure was refined from the single-crystal X-ray data and shown to be orthorhombic of the UPd2Sn-type (s.g. Pnma). The compound orders antiferromagnetically at TN 1/4 15K: All the bulk properties show temperature variations characteristic of systems with strong electronic correlations, with a large negative paramagnetic Curie temperature (yCW 1/4 80 K), a negative logarithmic slope of the resistivity (cK 1/4 11mO cm=K) and a strongly enhanced electronic specific heat (g 1/4 400 mJ=molK2). Thus NpPd2Sn may be a novel heavy-fermion system, one of very few known so far amidst Np-based intermetallics.JRC.E.6-Actinides researc