Direct Measurement of the Absolute Seebeck Coefficient for Pb and Cu at 300 K to 450 K

Abstract

The utilization of thermal fluctuations or Johnson/Nyquist noise as a spectroscopic technique to experimentally measure transport properties is applied to Pb and Cu metal films. Through cross-correlation and autocorrelation functions obtained from power spectral density measurements, multiple transport coefficients are obtained through the Green-Kubo formalism. Supported rigorously by the underlying fluctuation-dissipation theory, this new experimental technique provides a direct measurement of absolute thermoelectric coefficients in addition to the electrical resistivity, electronic contribution to thermal conductivity, Lorentz number and various diffusion coefficients. This work reports the validation results of the experiment accomplished through the use of materials with thermoelectric properties widely accepted by the thermoelectric community, Pb and Cu. Further validation of the data was accomplished by comparing resistivity results to standard collinear four-probe resistivity measurements. Thermal fluctuation data for Pb at 300 K resulted in 5.9% and 2.02% agreement with the published Seebeck and four-probe resistivity data respectively. The Cu thermal fluctuation measurements at 300 K showed agreement within 3.76% and 6.14% for the published Seebeck and four-probe data respectively thus lending further credibility to the experimental method and underlying theory.