Europhys. Lett.
Volume 74, Number 1, April 2006
Page(s) 96 - 102
Section Condensed matter: structural, mechanical and thermal properties
Published online 01 March 2006
Europhys. Lett., 74 (1), pp. 96-102 (2006)
DOI: 10.1209/epl/i2005-10508-1

Glass-like behaviour of thermal conductivity of $\chem{CH_4}$- $\chem{CD_4}$ solid solutions

P. Stachowiak1, E. Pisarska1, A. Jezowski1 and A. I. Krivchikov2

1  Institute for Low Temperatures and Structure Research, Polish Academy of Sciences PN 1410, 50-950 Wroclaw, Poland
2  Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine - 47 Lenin Ave., Kharkov 61103, Ukraine

received 12 December 2005; accepted in final form 9 February 2006
published online 1 March 2006

Some mixed crystals show a low-temperature thermal-conductivity dependence on temperature similar to that of amorphous solids. This phenomenon is usually ascribed to a disorder of another kind. In the current paper we report results of measurements of the thermal conductivity of $\chem{CH_4}$- $\chem{CD_4}$ solid solution which also displays a glass-like behaviour for some concentrations of deuterated methane. Here, however, the disorder appearing at these concentrations of $\chem{CD_4}$ cannot account for the characteristic plateau. Instead, we explain it in terms of an enhancement of the phonon-rotation interaction resulting from lowering the symmetry of the molecular field.

66.70.+f - Nonelectronic thermal conduction and heat-pulse propagation in solids; thermal waves.
63.20.Mt - Phonon-defect interactions.

© EDP Sciences 2006