Electronic transport properties of intermediately coupled superconductors: PdTe2 and Cu0.04PdTe2

Abstract

We have investigated the electrical resistivity, Seebeck coefficient and thermal conductivity of PdTe2 and 4% Cu intercalated PdTe2 compounds. Electrical resistivity for the compounds shows Bloch-Gruneisen type linear temperature (T) dependence for 100 K < T < 480 K, and Fermi liquid behavior (~ T^2) below 50 K. Seebeck coefficient data exhibit strong competition between Normal (N) and Umklapp (U) scattering processes at low T. Though our results indicate the transfer of charge carriers to PdTe2 upon Cu intercalation, it is difficult to discern any change in the Fermi surface of the compound by Nordheim-Gorter plots. The estimated Fermi energies of the compounds are quite comparable to good metals Cu, Ag and Au. The low T, thermal conductivity (k) of the compounds is strongly dominated by the electronic contribution, and exhibits a rare linear T dependence below 10 K. However, high T, k(T) shows usual 1/T dependence, dominated by U scattering process. The electron phonon coupling parameters, estimated from the low T, specific heat data and first principle electronic structure calculations suggest that PdTe2 and Cu0.04PdTe2 are intermediately coupled superconductors.