Variations of thermoelectric properties of Mg{sub 2.2}Si{sub 1−y}Sn{sub y−0.013}Sb{sub 0.013} materials with different Si/Sn ratios
- School of Materials Science and Engineering, BeiHang University, Beijing 100191 (China)
- State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China)
Mg{sub 2}Si–Mg{sub 2}Sn solid solutions are a promising class of thermoelectric materials. Mg{sub 2.2}Si{sub 1−y}Sn{sub y−0.013}Sb{sub 0.013} compounds with different Si/Sn ratios were prepared by B{sub 2}O{sub 3} “flux” method followed by hot-pressing. The effect of Si/Sn ratio on the thermoelectric properties of the Mg{sub 2}Si–Mg{sub 2}Sn solid solutions at a fixed Sb doping level were measured in the temperature range 300–760 K. With the increase of Sn content (0.3≤y≤0.7), power factors are improved and lattice thermal conductivity decreased. Band convergence induced by Si/Sn ratio leads to enhanced effective mass and the materials parameter β which qualifies a kind of thermoelectric material is improved evidently. A maximum ZT of ∼1.1 at ∼760 K was achieved for the Mg{sub 2.2}Si{sub 0.3}Sn{sub 0.7–0.013}Sb{sub 0.013} sample arising from a high power factor of ∼4×10{sup -3} W m{sup −1} K{sup −2} and a low lattice thermal conductivity of ∼1.6 W m{sup −1} K{sup −1} at ∼760 K. - Graphical abstract: (a)Temperature dependence of power factor of Mg{sub 2.2}Si{sub 1−y}Sn{sub y−0.13}Sb{sub 0.013} samples. (b)Temperature dependence of lattice thermal conductivity of Mg{sub 2.2}Si{sub 1−y}Sn{sub y−0.13}Sb{sub 0.013} samples. (c)Temperature dependence of dimensionless figure of merit ZT of Mg{sub 2.2}Si{sub 1−y}Sn{sub y−0.13}Sb{sub 0.013} samples. - Highlights: • Mg{sub 2.2}Si{sub 1−y}Sn{sub y−0.013}Sb{sub 0.013} was prepared by B{sub 2}O{sub 3} ''flux'' method followed by hot-pressing. • Band convergence leads to enhanced m{sup ⁎} and improved materials parameter β. • ZT{sub max} of ∼1.1 at ∼760 K was achieved for the Mg{sub 2.2}Si{sub 0.3}Sn{sub 0.7−0.013}Sb{sub 0.013} sample.
- OSTI ID:
- 22451124
- Journal Information:
- Journal of Solid State Chemistry, Vol. 220; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thermoelectric properties of p-type Ag{sub 1−x}(Pb{sub 1−y}Sn{sub y}){sub m}Sb{sub 1−z}Te{sub m+2}
Crystal structure, characterization and thermoelectric properties of the type-I clathrate Ba{sub 8-y}Sr{sub y}Al{sub 14}Si{sub 32} (0.6{<=}y{<=}1.3) prepared by aluminum flux