Effect of Excessive Antimony on the Thermoelectric and Transport Properties of Mg3Sb2 Synthesized by Controlled Melting, Pulverizing Followed by Vacuum Hot Pressing

Zintl compounds were recognized as very good thermoelectric candidate due to their characteristics electron-crystal phonon- glass properties. Mg(3)Sb(2)is a known Group II-V Zintl semiconductor. This compound is a well-established thermoelectric material and many of recent works focus on this compound due to its intrinsic low thermal conductivity. The band gap of this compound has been shown to be optimum, making it a promising thermoelectric material. This work introduces a new synthetic method and analyzes the thermoelectric properties found using this method. The single phase of Mg(3)Sb(2)was synthesized by melting elemental shots at 1173 K for 1 hour in a controlled inert Ar gas atmosphere in a tapped graphite crucible followed by vacuum hot pressing at 873 K for 4 hours. X-ray diffraction and scanning electron microscopy were carried out to investigate existing phases and surface morphology respectively. Thermoelectric properties in terms of Seebeck coefficient, electrical conductivity, and thermal conductivity were evaluated and the results are discussed in comparison to analogous studies. Transport properties were also evaluated and discussed. Single phase magnesium antimonide was found with a nominal formula of Mg(3.8)Sb(2)and showed a comparable ZT value which is similar to 0.24 at 873 K. [GRAPHICS] .