Session V9 - Advanced Solid State Electronic Cooling and Power Generation I.
FOCUS session, Thursday morning, March 15
Room 201, Washington State Convention Center
The lattice thermal conductivity of semiconducting Ge clathrates crystals (type I) is investigated by evaluating the linear response theory heat current correlation functions using molecular dynamics. Clathrate crystals with and without guest atoms in their fullerane cages are studied. In comparison with that of diamond-phase Ge, the clathrate conductivity is reduced by approximately one order of magnitude due to the open framework itself. The addition of an encapsulated (rattling) Sr guest atom produces a further order of magnitude reduction in the conductivity, making it comparable to that of amorphous Ge. Our results are consistent with experiments, and have impact on the search for improved thermoelectric materials.