Mechanical alloying of a new promising thermoelectric material, Sb3Zn4

We report in this paper a study of the mechanical alloying (MA) process for a high-performance p-type thermoelectric material, Sb3Zn4. Three samples belonging to the homogeneity range of Sb3Zn4 and one with a slightly higher content in zinc have been prepared by MA. From systematic analyses of the latter one, the mechanism of formation for Sb3Zn4 has been studied. The powders have been characterised by X-ray diffraction, scanning electron microscopy and differential scanning calorimetry. The results lead us to conclude that MA powder of Sb3Zn4 is produced by solid state diffusion. With the experimental conditions used in this work, single phase material can not be obtained directly from MA, its formation requires a further heating at low temperatures. Since this heating occurs in the industrial processes for solidification and net-shaping to thermoelectric devices, MA seems to be a good alternative method of preparation for Sb3Zn4. (C) 2002 Elsevier Science B.V. All rights reserved.