Synthesis of Bi0.5Sb1.5Te3 Thermoelectric Powder Using an Oxide-Reduction Process

The present study focused on synthesis of Bi0.5Sb1.5Te3 thermoelectric powder using an oxide-reduction process. The phase structure and particle size of the synthesized powders were analyzed using x-ray diffractometry and scanning electron microscopy. The synthesized powder was sintered using the spark plasma sintering method. The thermoelectric properties of the sintered body were evaluated by measuring the Seebeck coefficient, electrical resistivity, and thermal conductivity. Bi0.5Sb1.5Te3 powder was synthesized using a combination of mechanical milling, calcination, and reduction processes, using a mixture of Bi2O3, Sb2O3, and TeO2 powders. The sintered body of the oxide-reduction-synthesized Bi0.5Sb1.5Te3 powder showed p-type thermoelectric characteristics. The thermoelectric properties of the sintered bodies depended on the reduction time. After being reduced for 2 h at 663 K, the sintered body of the Bi0.5Sb1.5Te3 powder showed a figure of merit of approximately 1.0 at room temperature.