Detailed investigation of thermal and electron transport properties in strongly correlated compound Ce₆Pd₁₂In₅ and its nonmagnetic analog La₆Pd₁₂In₅

An in-depth study of thermal and electron transport properties including thermal conductivity kappa(T), thermoelectric power S(T), and electrical resistivity rho(T) of the heavy fermion Kondo lattice Ce6Pd12In5 and its nonmagnetic reference compound La6Pd12In5 is presented. The absolute kappa(T) value of Ce6Pd12In5 is smaller that than of La6Pd12In5, which indicates that conduction electron-4f electron scattering has a large impact on the reduction of thermal conductivity. The isolated 4f electron contributions to the electrical resistivity q(4f) (T), electronic thermal resistivity displayed in the form W-el;4f (T)center dot T, and thermoelectric power S-4f (T) reveal a low-and high-temperature -lnT behaviour characteristic of Kondo systems with strong crystal-electric field (CEF) interactions. The analysis of phonon scattering processes of lattice thermal conductivity kappa(ph)(T) in (Ce, La)(6)Pd12In5 was performed over the whole accessible temperature range according to the Callaway model. In the scope of a theoretical approach based on the perturbation type calculation, we were able to describe our experimental data of rho(4f) (T) and W-el;4f (T)center dot T by using the model incorporating simultaneously the Kondo effect in the presence of the CEF splitting, as it is foreseen in the framework of the Cornut-Coqblin and Bhattacharjee-Coqblin theory. Considering the fact that there are not many cases of similar studies at all, we also show the numerical calculations of temperature-dependent behaviour of spin-disorder resistivity rho(s)(T), magnetic resistivity rho(4f) (T), and occupation number hNii due to the various types of degeneracy of the ground state multiplet of Ce3+ (J = 5/2). Published by AIP Publishing