Magnetic, electrical transport, and thermal properties of a uranium intermetallic compoundUCu5In

Abstract

A ternary intermetallic compound ${\mathrm{UCu}}_{5}\mathrm{In}$ has been studied by means of magnetization, electrical resistivity, magnetoresistivity, thermopower, thermal conductivity, heat-capacity, and thermal-expansion measurements. The experimental findings reveal ${\mathrm{UCu}}_{5}\mathrm{In}$ to be antiferromagnetically ordered ${(T}_{N}=25\mathrm{K})$ dense Kondo system ${(T}_{K}=24\mathrm{K})$ with a considerable enhancement of the effective mass of conduction electrons at low temperatures, yielding the Sommerfeld coefficient $\ensuremath{\gamma}(0)$ of about 240 mJ/(mole ${\mathrm{K}}^{2}).$ Although the electrical resistivity and the thermopower of ${\mathrm{UCu}}_{5}\mathrm{In}$ shows features characteristic of interplay of Kondo and crystal-field effects, the magnetoresistivity does not exhibit behavior expected for Kondo systems being large and positive even well above ${T}_{N}.$ Consistent explanation of the latter results is attempted by considering the role of magnetic precursor effects and/or interfacelike effects due to the presence of nonmagnetic layers.