Thermal conductivity and heat capacity of LuMgCu4

This paper reports on the measurements of the thermal conductivity κ and electrical resistivity ρ in the temperature range 5–300 K and the heat capacity at constant pressure Cp in the range 80–300 K for the metallic nonmagnetic compound LuMgCu4. The experimental values of κ and Cp for the LuMgCu4 compound are compared with the corresponding data available in the literature for the light heavy-fermion compound YbMgCu4. It is shown that, in the low-temperature range (5–20 K), the phonon thermal conductivity κph of YbMgCu4 is lower than κph of LuMgCu4 as a result of phonon scattering from magnetic moment fluctuations of the Yb 4f electrons and, conversely, the heat capacity of LuMgCu4 in the range 80–300 K is lower than that of YbMgCu4 because the heat capacity of the latter compound has an additional magnetic component.