Heat capacity and thermopower coefficient of the carbon preform of sapele wood

Autor: A.R. de Arellano-López, D. Wlosewicz, H. Misiorek, C. Sułkowski, Andrzej Jeżowski, Julián Martínez-Fernández, B. I. Smirnov, I. A. Smirnov, L. S. Parfen’eva
Rok vydání: 2009
Předmět:
Zdroj: Physics of the Solid State. 51:2252-2256
ISSN: 1090-6460
1063-7834
DOI: 10.1134/s1063783409110092
Popis: This paper reports on measurements of the heat capacity at constant pressure Cp in the 80–300-K temperature interval and the thermopower coefficient S at 5–300 K of the carbon preform of sapele wood, which was prepared at the carbonization temperature of 1000°C. Measurements of Cp(T), our previous data on the phonon thermal conductivity, and literature information on the sound velocity have been used to calculate the phonon mean free path l(T) for this material. It has been shown that within the temperature interval 200–300 K, l is constant and equal to 11 A, a figure matching the size of the nanocrystallites (“graphite fragments”) making up the carbon framework of the sapele carbon preform. The high-temperature parts of S(T) have been found to follow a linear course characteristic of diffusive thermopower for the degenerate state of charge carriers, with only one type of charge carriers present. The anisotropy of the thermopower coefficient has been estimated.
Databáze: OpenAIRE
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