Westudied the low-temperature thermoelectric properties of single crystals of Mg3Sb2-xBix (0≤x≤2) grown by the Bridgman method. The crystals are well aligned along the hexagonal c axis as documented in the huge anisotropy of the electrical resistivity; ρ//c/ρ⊥c = 100 for x = 2. Upon increasing x, the semiconducting behaviour in ρ(T) changes to the metallic behaviour, and the Seebeck coefficient S(T) at room temperature decreases from 590 μVK-1 for x = 0 to 67 μVK-1 for x=2. Although the thermal conductivity at 300 Kis as low as 0.88WmK-1 for x = 0.7, the large resistivity of 1Ωcm leaves the figure of merit, ZT, at a low level of 5.8 × 10-3 at 300 K.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2014R1A2A1A11050401).
© 2015 IOP Publishing Ltd.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Polymers and Plastics
- Metals and Alloys