Coherent description of electrical and thermal impurity-and-phonon limited transport in simple metals

The electrical resistivity, thermoelectric power and electronic thermal conductivity of simple (isotropic) metals are studied in a uniform way. Starting from results of a variational solution of the Boltzmann equation, a generalized Matthiessen rule is used in order to superpose the inelastic (or not) electron-phonon and elastic electron-impurity scattering cross sections ("matrix elements"). The temperature dependence relative to these processes is given through simple functions and physical parameters over the usually investigated range of temperature for each transport coefficient. The coherence of such results is emphasized.Comment: 22 pages, 5 figures; to appear in International Journal of Modern Physics

Behavior of the thermopower in amorphous materials at the metal-insulator transition

Published versio

Analysis of Experimental Conditions for Simultaneous Measurements of Transport and Magnetotransport Coefficients of High Temperature Superconductors

Experimental conditions for simultaneous measurements of transport coefficients of high temperature superconductors in zero and non-zero magnetic fields are analysed. Test measurements of the thermal conductivity, the thermoelectric power and the Nernst - Ettingshausen effect of a textured Bi2212 sample are reported in an external magnetic field of 2T. Errors related to parameters of the thermocouple used and to the spurious heat flows are discussed for a new experimental set-up built based on a closed cycle helium refrigerator. Possible optimising of experimental conditions is suggested.Comment: 9 pages + 4 figures. accepted for publication in Cryogenic

General Formula for the Thermoelectric Transport Phenomena based on the Fermi Liquid Theory: Thermopower, Nernst Coefficient, and Thermal Conductivity

On the basis of the linear response transport theory, the general expressions for the thermoelectric transport coefficients, such as thermoelectric power (S), Nernst coefficient (\nu), and thermal conductivity (\kappa), are derived by using the Fermi liquid theory. The obtained expression is exact as for the most singular term in terms of 1/\gamma_k^* (\gamma_k^* being the quasiparticle damping rate). We utilize the Ward identities for the heat current which is derived by the local energy conservation law. Based on the derived expressions, we can calculate various thermoelectric transport coefficients within the framework of the Baym-Kadanoff type conserving approximation. Thus, the present expressions are very useful for studying the strongly correlated electrons such as high-Tc superconductors, organic metals, and heavy Fermion systems, where the current vertex corrections are expected to play important roles. By using the derived expression, we calculate the thermal conductivity \kappa in a free-dispersion model up to the second-order with respect to U. We find that it is slightly enhanced due to the vertex correction for the heat current, although the vertex correction for electron current makes the conductivity (\sigma) of this system diverge, reflecting the absence of the Umklapp process.Comment: 22 pages, 11 figures; accepted for publication in PR

Crystal-field effects on the thermal conductivity of localized spin metallic compounds

The influence of the crystal-electric-field (CEF) splitting on the thermal conductivity is calculated on the basis of a two-level system model applicable to intermetallic magnetic compounds. The localized spin scattering contribution kappa(s), in a manner similar to the total electronic thermal conductivity kappa(e), shows a larger increase at low and intermediate temperatures as compared to the case iii which-no crystal-electric-field splitting is taken into account. The influence of some theoretical parameters is also discussed. It is shown that the CEF effect enhances the effect of the magnetic scattering potential, and impurity contributions screen such an enhancement at temperatures below the Debye temperature. Other scattering contributions, e.g., electron-phonon and electron impurities, are also taken into account in our calculation. The theory is in quantitative agreement with data on RA1(2) systems taken as test cases, and leads to values of the level splitting in the 50 K range