Thermoelectric properties of Te-doped Mg3Sb2 synthesized by spark plasma sintering

• Published in: Physica. B, Condensed matter Condensed matter, 2020-07, Vol.588, p.412173, Article 412173
• Main Authors: Tani, Jun-ichi, Ishikawa, Hiromichi
• Format: Article
• Language: English
• Subjects: Antimony; Carrier transport; Chemical synthesis; Diffraction; Diffraction patterns; Electric properties; Electron backscatter diffraction; Figure of merit; Grain size; Impurity doping; Magnesium antimonide; Microstructure; Plasma sintering; Spark plasma sintering; Tellurium; Thermoelectric materials; Thermoelectric power generation; Thermoelectric properties; Transport properties; X ray powder diffraction
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2020.412173

With the increase in population, energy demand is consequently rising. The development and application of thermoelectric materials is among the approaches to address this issue. Herein, n-type Te-doped Mg3Sb2 (Mg3Sb2−xTex; x = 0–0.08) samples were directly synthesized from Mg, Sb, and Te powders by spark plasma sintering at 973 K and characterized in terms of carrier transport and thermoelectric properties. Powder X-ray diffraction patterns revealed the presence of α-Mg3Sb2 (major phase) and MgO (traces), while electron backscatter diffraction revealed the average grain sizes of 247 and 91 μm for samples with x = 0 and 0.05, respectively. Te content was shown to influence the carrier transport properties. Particularly, the maximal dimensionless thermoelectric figure of merit (ZT) of Te-doped Mg3Sb2 was obtained as ~1.0 for x = 0.03–0.08 at 768 K.