Relating phase transition heat capacity to thermal conductivity and effusivity in Cu2Se
Artikel i vetenskaplig tidskrift, 2016

Accurate measurement of thermal conductivity is essential to determine the thermoelectric figure-of-merit, zT. Near the phase transition of Cu2Se at 410 K, the transport properties change rapidly with temperature, and there is a concurrent peak in measured heat capacity from differential scanning calorimetry (DSC). Interpreting the origin as a broad increase in heat capacity or as a transient resulted in a three-fold difference in the reported zT in two recent publications. To resolve this discrepancy, thermal effusivity was deduced from thermal conductivity and diffusivity measurements via the transient plane source (TPS) method and compared with that calculated from thermal diffusivity and the two interpretations of the DSC data for heat capacity. The comparison shows that the DSC measurement gave the heat capacity relevant for calculation of the thermal conductivity of Cu2Se. The thermal conductivity calculated this way follows the electronic contribution to thermal conductivity closely, and hence the main cause of the zT peak is concluded to be the enhanced Seebeck coefficient.

heat capacity

copper selenide

differential scanning calorimetry


thermal effusivity


D. R. Brown

California Institute of Technology (Caltech)

United States Department of Energy

Richard Heijl

Chalmers, Kemi och kemiteknik, Tillämpad kemi

K. A. Borup

Aarhus Universitet

B. B. Iversen

Aarhus Universitet

Anders Palmqvist

Aarhus Universitet

G. J. Snyder

Northwestern University

California Institute of Technology (Caltech)

Physica Status Solidi - Rapid Research Letetrs

1862-6254 (ISSN) 1862-6270 (eISSN)

Vol. 10 8 618-621





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