Assessing the role of filler atoms on the thermal conductivity of filled skutterudites

We investigate the lattice thermal conductivity of a series of La- and Yb-filled skutterudite antimonides by modeling different phonon-scattering parameters using the Debye approximation. We also investigate the contributions of the different phonon-scattering mechanisms in understanding the relative importance of the different scattering mechanisms on filled skutterudites. We find that increasing the filler atom concentration effectively increases both point defect scattering and resonance scattering of phonons. In addition, point defect scattering can have a substantial effect in lowering the thermal conductivity of skutterudites. These results help elucidate the role of the different scattering mechanisms on the thermal conductivity of these materials. (c) 2006 American Institute of Physics.