The role of phonon dispersion in the prediction of the thermal conductivity of germanium between temperatures of 2 K and 1000 K is investigated using the Holland approach. If no dispersion is assumed, a large, nonphysical discontinuity is found in the transverse phonon relaxation time over the entire temperature range. However, this effect is masked in the final prediction of the thermal conductivity by the use of fitting parameters. As the treatment of the dispersion is refined, the magnitude of the discontinuity is reduced. At the same time, discrepancies between the high temperature predictions and experimental data become apparent, indicating that the assumed heat transfer mechanisms (i.e., the relaxation time models) are not sufficient to account for the expected thermal transport. Molecular dynamics simulations may be the most suitable tool available for addressing this issue.
Role of Phonon Dispersion in Lattice Thermal Conductivity Modeling
Contributed by the Heat Transfer Division for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received by the Heat Transfer Division June 13, 2003; revision received January 9, 2004. Associate Editor: G. Chen.
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Chung, J. D., McGaughey, A. J. H., and Kaviany, M. (June 16, 2004). "Role of Phonon Dispersion in Lattice Thermal Conductivity Modeling ." ASME. J. Heat Transfer. June 2004; 126(3): 376–380. https://doi.org/10.1115/1.1723469
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