Effects of defects and impurities on electronic properties in skutterudites

The transport properties of non-doped and doped skutterudites are discussed, based on results of the band structure calculation. The calculation is carried out by the full-potential linearized augmented plane-wave (FLAPW) method with the generalized gradient approximation (GGA). Firstly the electronic structure of doped CoSb₃ is calculated when an impurity atom is put in a void of the skutterudite structure. Secondly the thermoelectric power is calculated with the constant relaxation-time approximation in the skutterudite antimonides by using the realistic electron bands. RhSb₃ differs from IrSb₃ in the band structure near the Fermi level. This difference appears strongly in the thermoelectric power at a low doping case