Thermoelectric properties of Fe-doped CoSb3 prepared by mechanical alloying and vacuum hot pressing

Fe doped skutterudite CoSb3 with a nominal composition of FexCo4−xSb12 (0 ≤ x ≤ 2.5), were synthesized by mechanical alloying of elemental powders, and consolidated by vacuum hot pressing. Nanostructured, single-phase skutterudites were successfully produced for the compositions of x ≤ 1.5, while second phase was found to form in case of x ≥ 2. Thermoelectric properties including thermal conductivity from 300 to 600 K were measured and discussed. Lattice thermal conductivity was greatly reduced by introducing Fe doping up to x ≤ 1.5 as well as by increasing phonon scattering in nanostructured skutterudite, leading to enhancement in the thermoelectric figure of merit.