Structural, magnetic and transport properties of single-crystalline U2Pt2In

Single crystals of the heavy-electron compound U2Pt2In have been grown by a modified mineralization technique. The x-ray structure refinement shows that U2Pt2In single crystals form in the Zr3Al2 structure, instead of the U3Si2 structure reported for polycrystalline material. The polymorphism of U2Pt2In is attributed to the experimental parameters, such as pressure and temperature, during the sample preparation process. The single-crystal susceptibility data reveal a weak maximum for chi(c) at T-max = 7.9 K indicating the presence of short-range antiferromagnetic correlations, while chi(a) has the tendency to diverge at low T(T > 2 K). The electrical resistivity of the single crystals (T > 0.3 K) is best described by rho similar to T-alpha with alpha similar to 1.1(1) for I parallel to a and alpha similar to 0.3(2) for I parallel to c. The magnetic and transport data show pronounced deviations from the standard Fermi-liquid picture, and lead to a classification of U2Pt2In as a non-Fermi-liquid compound. As the origin of Nn behaviour in U2Pt2In we propose the proximity to a quantum critical point or Kondo disorder.