Heat transfer in crystalline clathrate hydrates at low temperatures

摘要

The experimental results on the thermal conductivity k(T) of crystalline Xe, CH₄, and THF clathrate hydratesudhave been analyzed. In a wide region of temperatures above 2 K, k(T) exhibits a behavior typical ofuddisordered solids, which depends weakly on their chemical composition, crystalline structure and microstructure.udThe results are discussed in the context of phenomenological models of phonon scattering by localudmodes. It has been found that the Xe clathrate has a feature unusual for glasses, namely, k(T) decreases almostudtwo-fold as the temperature increases from 50–100 K. The behavior of k(T) is presumably determinedudmainly by the strong phonon scattering on water molecules.