Structural Analysis and Properties of Bi2-xSbxTe3-ySey Prepared by Angular Extrusion
The purpose of this work is producing bismuth telluride based alloys with both well-orientated texture and fine grains to improve thermoelectric properties. The angular extrusion process was applied to Bi1.9Sb0.1Te2.7Se0.3 foils which were prepared by a liquid quenching method . The extrusion temperatures examined ranged from 380 to 540 °C. The microstructures of the specimens were characterized with an optical microscope and OIM. Recrystallized grains sizes ranging from 3.61 to 10.01 μm were obtained at these temperatures. The textures of the specimens show the basal plane preferably aligns along to the extruded direction. A maximum power factor of 4.18 × 10-3 W / mK2 was obtained in this work. These results indicate that the angular extrusion process is effective to improve the thermoelectric properties of bismuth telluride based alloy.
T. Hayashi et al., "Structural Analysis and Properties of Bi2-xSbxTe3-ySey Prepared by Angular Extrusion", Materials Science Forum, Vols. 503-504, pp. 567-572, 2006