Heat transfer in crystalline clathrate hydrates at low temperatures
A.I. Krivchikov, O.A. Korolyuk, and O.O. Romantsova
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Lenin Ave., Kharkov 61103, Ukraine
Received October 20, 2006
The experimental results on the thermal conductivity к(T) of crystalline Xe, CH4, and THF clathrate hydrates have been analyzed. In a wide region of temperatures above 2 K, к(T) exhibits a behavior typical of
disordered solids, which depends weakly on their chemical composition, crystalline structure and microstructure.
The results are discussed in the context of phenomenological models of phonon scattering by local modes. It has been found that the Xe clathrate has a feature unusual for glasses, namely, к(T) decreases almost two-fold as the temperature increases from 50–100 K. The behavior of к(T) is presumably determined mainly by the strong phonon scattering on water molecules.
PACS: 66.70.+f Nonelectronic thermal conduction and heat-pulse propagation in solids; thermal waves; PACS: 63.20.–e Phonons in crystal lattices; PACS: 63.20.Pw Localized modes; PACS: 63.50.+x Vibrational states in disordered systems.