Effect of Forming Process on Microstructure and Thermoelectric Properties of In4se3 Compound

Starting from elemental In and Se powders, polycrystalline In4Se3 compound samples were synthesized by mechanical alloying (MA) and subsequent hot pressing (HP). The phase evolution during mechanical alloying and the microstructure of the sintered samples were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA) and field emission scanning electron microscope (FE-SEM) respectively. It was found that In4Se3 compound could be synthesized by mechanical alloying of the elemental powders mixture only for 3h. The density and microstructure of In4Se3 compound could be improved by increasing HP temperature or pressure. A maximum power factor of 533μWm-1K-2 was obtained for the In4Se3 sample hot pressed at 450°C under a pressure of 120MPa.