Transport and magnetic properties of the superconductor NpPd5Al2

Abstract

Crystals of the transuranium superconductor NpPd5Al2 have been prepared by arc melting stoichiometric amounts of constituent pure metals (Np 99.9%, Pd 99.99%, Al 99.999%). The single crystals (extracted from the batch) were examined by x-ray diffraction, magnetization, resistivity, magnetoresistivity, Hall effect, thermoelectric power, and heat capacity measurements under magnetic fields and at low temperature along the main crystallographic directions. The superconductivity is observed at Tc ∼5 K. It is intrinsically related to the ZrNi2Al5 structure type (space group I4/mmm) and independent of the synthesis process. The specific heat measured down to 0.6 K shows that NpPd2Al5 is a nonmagnetic strong coupled type II superconductor presenting heavy fermion features (γe∼190 mJ mol−1 K−2). The determination of the critical field by electrical resistivity indicates high anisotropic Bc2 values: ∼4 T along [100] and ∼15 T along [001]. Magnetoresistivity, Hall effect, and thermopower measurements point to strong electronic correlations that could be at the origin of superconductivity in this transuranium intermetallic compound.

Source-reported materials — not catalogue approval

Similar papers