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)(S) is 160 μV/K at room temperature, while the electrical resistivity (ρ)(ρ) is 65mΩcm. The effects of chemical substitutions on the Ir site (Ru, Pd) and Sn site (In, Sb) have been investigated. The power factor (S2/ρ)(S2/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.