Physical and Structural Properties of Ternary Uranium Compounds in the U-Ni-Sn and U-Ni-In Systems

Abstract

New ternary uranium compounds of UNi 2 Sn and UNi 2 In have been prepared and found to crystallize in the MgCu 2 Al-type structure. On these compounds and UNi 4 Sn, UNi 4 In and U 3 Ni 3 Sn 4 with cubic structures, we report the results of electrical resistivity, thermoelectric power, magnetic susceptibility and specific heat measurements. Of the five compounds, only U 3 Ni 3 Sn 4 exhibits a moderately heavy-fermion behavior at low temperatures. The other four compounds, where the distance between the U atom and the nearest-neighboring Ni atom is almost the same as in U 3 Ni 3 Sn 4 , are, however, enhanced Pauli paramagnets. No compounds show magnetic or superconducting transition down to 1.6 K.