Preparation and Thermoelectric Properties of Zinc Antimonide

We have demonstrated two processes for the synthesis of zinc antimonide powder using rapid melt cooling: melt spinning and cooling in a liquid. The elemental and phase compositions and surface morphology of hot-pressed undoped and 3 wt % In-doped β-Zn4Sb3 samples have been studied by scanning electron microscopy, X-ray diffraction, and optical microscopy, and their Seebeck coefficient, electrical conductivity, and thermal conductivity have been measured in the range 300–700 K. Indium doping has been shown to reduce the lattice thermal conductivity of the material by a factor of 1.5. The 600-K thermoelectric figure of merit of the undoped sample (ZT = 0.8) is half that of the doped sample (ZT = 1.5). We have assessed the effect of thermal cycling in the range 300–700 K on the Seebeck coefficient and electrical conductivity of the samples.