Engineering electrical transport in α-MgAgSb to realize high performances near room temperature. Issue 24 (8th June 2018) - Lei, Jingdan
Abstract : Realizing high performances of α-MgAgSb near room temperature by engineering electrical transport through manipulating a spark plasma sintering system. Abstract : 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.