Thermoelectric properties of strongly correlated compounds AnPd3 (An = Pu, Np)
We present, for the first time, the thermoelectric properties of NpPd3 and PuPd3 compounds. We show that the Seebeck coefficient of these materials is enhanced and its magnitude and temperature dependence are characteristic of dense Kondo systems in which 5f -states are present in the vicinity of the Fermi level. The electrical resistivity also shows characteristic behavior of Kondo lattices in these materials. For cubic NpPd3 a sharp transition in electrical resistivity and thermopower together with a change of sign of S (T) at the Néel temperature, indicate a first order nature of the magnetic transition. This transition is probably accompanied by a large Fermi-surface reconstruction. Further studies, however, are required to better understand the electronic structure of cubic NpPd3 and other AnPd3 phases. We have also estimated power factor (S^2/rho) of the samples studied. We find out that it is relatively high although much smaller than observed in rare-earth-based REPd3 phases, especially CePd3.