Lorenz Numbers of Pure Aluminum, Silver, and Gold at Low Temperatures

Abstract

Measurements have been made of the thermal and electrical conductivities at low temperatures on specimens of pure aluminum, silver, and gold. The resistivities caused by scattering of the electrons by lattice waves and by impurities have been separated and the Lorenz number has been deduced for these specimens. The Lorenz number calculated from the impurity resistivities for these pure metals agrees with the theoretical Sommerfeld value within an experimental error of about [Formula: see text]. The possible influence of an electron–electron interaction on these results is discussed.

Very-high thermal and electrical conductivity in overpressure-processed Bi2Sr2CaCu2O8+x wires

“…Predictions of the Wiedemann-Franz law are in good agreement with experiments at low temperatures and zero magnetic field, provided that the phonon contribution to thermal transport is negligible and that electron scattering processes are elastic [18,19]. In the case of Ag, very few studies are present in the literature and show that L varies with T going from ≈ 2.4×10 −8 WΩK −2 at 2K to ≈ 1×10 −8 WΩK −2 at 15K [8,20]. To the best of our knowledge, there are no published data over a wider range of cryogenic temperatures or at fields higher than 0.5T [8].…”

Experimental determination of phonon thermal conductivity and Lorenz ratio of single crystal metals: Al, Cu, and Zn

“…In the past, due to the limited availability of large magnetic fields and convenient methods to measure thermal conductivity while applying magnetic fields, very few single crystal metals were explored in transverse field to extract the phonon thermal conductivity or the Lorenz ratio. Some metals, such as Al 18 , Cu 6,19,20,25 , Zn 21 , Au 18 , Ag 18 , have results for their Lorenz ratio utilizing instead of . However, the method employed here lacks the functionality of estimating from .…”

“…Only a few results have been reported on the phonon thermal conductivity and Lorenz ratio of single crystal metals [5][6][7][18][19][20][21]25 . These limited data are due to the fact that the experimental setup is not easy to realize in the laboratory, controlling a large field and temperature simultaneously.…”

Photo-Thermoelectric Conversion of Plasmonic Nanohole Array

“…The thermal conductivities of the Ag film and nanoholes were estimated by using the Wiedemann-Frantz law, which states that the ratio of the thermal and electrical conductivities of a metal is proportional to the temperature [20]. The Lorenz number for Ag, 2.42 × 10 −8 W Ω/K 2 , was used for this estimation [21,22]. The estimated thermal conductivities of the Ag film and nanoholes, being 88.1 and 58.0 W/m•K, respectively, are much greater than those of the resistant polymer and air [23].…”