Engineering electrical transport in α-MgAgSb to realize high performances near room temperature

• Published in: Physical chemistry chemical physics : PCCP 2018-06, Vol.2 (24), p.16729-16735
• Main Authors: Lei, Jingdan, Zhang, De, Guan, Weibao, Cheng, Zhenxiang, Wang, Chao, Wang, Yuanxu
• Format: Article
• Language: English
• Subjects: Carrier density; Electrical resistivity; Lattice vacancies; Plasma sintering; Point defects; Power factor; Room temperature; Spark plasma sintering; Thermal conductivity; Thermoelectric materials; Transport properties
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c8cp02186d

α-MgAgSb shows promise as a potential new low-temperature thermoelectric (TE) material and has been widely researched recently. We explored the effects of sintering conditions on the properties of MgAgSb-based thermoelectric materials through manipulating a spark plasma sintering system (SPS), where Ag vacancies and Mg point defects play a dominant role. The transport properties of MgAgSb were optimized effectively and efficiently, especially for electrical transport. As a result, we obtained a steady power factor (PF) of ∼17 μW cm −1 K −2 , owing to the optimal carrier concentration of 9.8 × 10 19 cm −3 . Additionally, α-MgAgSb exhibits an ultralow lattice thermal conductivity of around 0.45 Wm −1 K −1 at 375 K. More importantly, a high ZT value of 0.85 was achieved below 375 K, approaching room temperature. Realizing high performances of α-MgAgSb near room temperature by engineering electrical transport through manipulating a spark plasma sintering system.