Glass-like thermal transport in symmetry-broken clathratesE. Kaneshita1, 2 and T. Nakayama3, 4
1 Advanced Photon Source, Argonne National Laboratory - 9700 South Cass Avenue, Argonne, IL 60439, USA
2 Yukawa Institute for Theoretical Physics, Kyoto University - Kyoto 606-8502, Japan
3 Materials Science Division, Argonne National Laboratory - 9700 South Cass Avenue, Argonne, IL 60439, USA
4 Toyota Physical and Chemical Research Institute - Nagakute, Aichi 480-1192, Japan
received 20 January 2009; accepted in final form 20 May 2009; published June 2009
published online 19 June 2009
We present the quantitative interpretation for the glass-like behavior of thermal conductivities for type-I clathrate compounds involving off-centered guest ions. It is shown that the dipole-dipole interaction generated in cage/guest-ion systems is crucial to reproduce the characteristics of thermal conductivities for these symmetry-broken clathrates. The above scenario also explains well the difference of between the p-type and the n-type -BGS found recently by K. Suekuni et al. (Phys. Rev. B, 77 (2008) 235119.)
61.72.Bb - Theories and models of crystal defects.
66.35.+a - Quantum tunneling of defects.
61.43.-j - Disordered solids.
© EPLA 2009