Expanding the investigation of the thermoelectric properties of rare-earth-filled skutterudites

There is increasing interest in the skutterudite family of compounds as potential thermoelectric materials mainly due to the marked reduction in the thermal conductivity that occurs when voids in the structure are filled with "guest" atoms. The "rattlling" of these void-fillers atoms damps the phonon propagation through the lattice. The phonon scattering mechanism(s) are not yet completely understood. Ongoing research focuses on compensating for the charge of the void-filling ions and finding the optimum void filler that yields maximal reduction in the thermal conductivity while maintaining favorable electronic properties. Thus far published data on Ge and Fe as charge compensators resulting in P-type samples has been reported. In this paper we present data on skutterudites incorporating Sn for charge compensation.