Synthesis, crystal structure and thermoelectric properties of IrSn1.5Te1.5 -based skutterudites

The mixed anion skutterudite IrSn1.5Te1.5 has been synthesized and characterized by X-ray powder diffraction, thermopower and electrical resistivity measurements. Structural analysis reveals that Sn and Te order in layers perpendicular to the [111] direction of the skutterudite unit cell, and a distortion of the anion sublattice is evident. The thermopower ( S ) is 160 μV/K at room temperature, while the electrical resistivity ( ρ ) is 65 m Ω cm . The effects of chemical substitutions on the Ir site (Ru, Pd) and Sn site (In, Sb) have been investigated. The power factor ( S 2 / ρ ) was found to improve with In substitution but, at 0.9 μW/K2 cm, is too small for this material to be useful for thermoelectric applications.