Fizika Nizkikh Temperatur: Volume 44, Number 8 (August 2018), p. 1073-1081 ( to contents , go back )
Isochoric thermal conductivity of solid 2-propanol
V.A. Konstantinov, V.V. Sagan, and А.V. Karachevtseva
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauky Ave., Kharkiv 61103, Ukraine
Received February 2, 2018
Isochoric thermal conductivity of solid 2-propanol C3H7OH has been measured for samples of different densities in the temperature range from 140 K and up to melting. It is found that thermal expansion significantly affects the temperature dependence of thermal conductivity in the monohydric alcohols studied at premelting temperatures. The isochoric thermal conductivity of all samples decreases with increasing temperature weaker than at a saturated vapor pressure and deviates strongly from the κ ∝ 1/T dependence. The experimental results are described in the frame-work of a model involving the transfer of heat by the propagons and diffusons; we discuss its principled difference from the simple Debye model, which does not take into account the dispersion and the real density of phonon states. The contributions of propagons and diffusons in 1- and 2-propanol are calculated and a comparison of thermal conductivities of isomers has been fulfilled. It was found that the diffusons contribution is much higher than the propagons contribution, and in 2-propanol both contributions are significantly smaller than in 1-propanol. It is shown that the coefficients Ai responsible for the propagons contribution depend essentially on the density, while the coefficients Bi describing the diffusons contribution is practically constant.
PACS: 66.70.–f Nonelectronic thermal conduction and heat-pulse propagation in solids; thermal waves.
Key words: thermal conductivity, crystalline propanol, propagons, diffusons.
Published online: June 27, 2018