Texture and thermoelectric properties of hot-extruded Bi2Te3 compound

This paper concerns about the applicability of extrusion process to fabricate Bi2Te3 thermoelements. High quality products were obtained by hot-extrusion method and their texture and the thermoelectric properties measured. The hot-extruded material had very fine grains derived from dynamic recrystallization. It was found that hot-extruded material has a ring-like texture in which the normal to the basal plane orients to the radial direction and 〈110〉 orients to the extrusion direction. Figure of merit of the extrudate increases with decreasing extrusion temperature and the value of the product extruded at 693 K showed a value corresponding to about 88% of unidirectionally solidified elements.