TRANSPORT AND MAGNETIC-PROPERTIES OF U(2)M(3)SI(5) SILICIDES (M=CO,RH,RU)

We report and discuss experimental data on the electrical resistivity p, thermoelectric power S, thermal conductivity kappa, specific heat C and magnetic susceptibility chi of polycrystalline U(2)M(3)Si(5) sili cides (M = Co, Rh, Ru). The magnetic and transport properties of these compounds depend strongly on the nature of the transition metal M. In U2Co3Si5, p(T) shows features that could be identified to Kondo syste ms while S(T) shows a two-peak structure. U2Rh3Si5 shows an antiferrom agnetic ordering at T-N similar to 25 K, which is accompanied by steep changes in both p(T) and S(T). U2Ru3Si5 behaves like a nonmagnetic co mpound and displays distinct anomalies in the low-temperature domains of p(T, H) and S(T, H). The lattice thermal conductivity varies as T-2 at low temperatures, suggesting a dominant scattering of the phonons by the conduction electrons.