Lattice dynamics of skutterudites: Inelastic x-ray scattering on CoSb₃

Skutterudite based materials are important for thermoelectric applications. In order to be able to tune the thermoelectric properties, it is necessary to understand the mechanism of thermal conductivity, which, in turn, is strongly influenced by the lattice dynamics. The lattice dynamics of the skutterudite parent compound CoSb₃ have been investigated by inelastic x-ray scattering experiments on single crystals. The experimental results are compared to predictions of different lattice dynamical calculations. The best description of the dispersion of the normal modes in the skutterudite lattice is obtained on the basis of an ab initio approach.