Synthesis and Thermoelectric Properties of InzCo4?xFexSb12 Skutterudites

The thermoelectric properties of In-filled and Fe-doped CoSb₃ (In _z Co_4−x - Fe _x Sb₁₂) skutterudites prepared by encapsulated induction melting were examined. A single δ-phase was obtained successfully by subsequent annealing at 823 K for 120 h. The Hall and Seebeck coefficients of the In _z Co_4−x Fe _x Sb₁₂ samples had positive signs, indicating p-type conduction. The electrical conductivity was increased by Fe doping, and the thermal conductivity was decreased by In filling due to phonon scattering. The thermoelectric properties were improved by In filling and Fe doping, and were closely related to the optimum carrier concentration and phonon scattering.