Thermoelectric properties of SnzCo8Sb24 skutterudites

Sn-filled CoSb3 skutterudite compounds were synthesized by the induction melting process. Formation of a single δ -phase of the synthesized materials was confirmed by X-ray diffraction analysis. The temperature dependences of the Seebeck coefficient, electrical resistivity and thermal conductivity were examined in the temperature range of 300–700 K. Positive Seebeck and Hall coefficients confirmed p -type conductivity. Electrical resistivity increased with increasing temperature, which shows that the Sn-filled CoSb3 skutterudite is a degenerate semiconductor. The thermal conductivity was reduced by Sn-filling because the filler atoms acted as phonon scattering centers in the skutterudite lattice. The lowest thermal conductivity was achieved in the composition of Sn0.25Co8Sb24.