Significant enhancement in thermoelectric performance of nanostructured higher manganese silicides synthesized employing a melt spinning technique
IR@NPL: CSIR-National Physical Laboratory, New Delhi
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| Title |
Significant enhancement in thermoelectric performance of nanostructured higher manganese silicides synthesized employing a melt spinning technique
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| Creator |
Muthiah, Saravanan
Singh, R. C. Pathak, B. D. Avasthi, Piyush Kuma Kumar, Rishikesh Kumar, Anil Srivastava, A. K. Dhar, Ajay |
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| Subject |
Chemistry
Materials Science Applied Physics/Condensed Matter Nanoscience/ Nanotechnology |
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| Description |
The limited thermoelectric performance of p-type Higher Manganese Silicides (HMS) in terms of their low figure-of-merit (ZT), which is far below unity, is the main bottle-neck for realising an efficient HMS based thermoelectric generator, which has been recognized as the most promising material for harnessing waste-heat in the mid-temperature range, owing to its thermal stability, earth-abundant and environmentally friendly nature of its constituent elements. We report a significant enhancement in the thermoelectric performance of nanostructured HMS synthesized using rapid solidification by optimizing the cooling rates during melt-spinning followed by spark plasma sintering of the resulting melt-spun ribbons. By employing this experimental strategy, an unprecedented ZT similar to 0.82 at 800 K was realized in spark plasma sintered 5 at% Al-doped MnSi1.73 HMS, melt spun at an optimized high cooling rate of similar to 2 x 10(7) K s(-1). This enhancement in ZT represents a similar to 25% increase over the best reported values thus far for HMS and primarily originates from a nano-crystalline microstructure consisting of a HMS matrix (20-40 nm) with excess Si (3-9 nm) uniformly distributed in it. This nanostructure, resulting from the high cooling rates employed during the melt-spinning of HMS, introduces a high density of nano-crystallite boundaries in a wide spectrum of nano-scale dimensions, which scatter the low-to-mid-wavelength heat-carrying phonons. This abundant phonon scattering results in a significantly reduced thermal conductivity of similar to 1.5 W m(-1) K-1 at 800 K, which primarily contributes to the enhancement in ZT.
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| Publisher |
Royal Society of Chemistry
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| Date |
2018-01-28
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://npl.csircentral.net/3945/1/Significant%20enhancement%20in%20thermoelectric.pdf
Muthiah, Saravanan and Singh, R. C. and Pathak, B. D. and Avasthi, Piyush Kuma and Kumar, Rishikesh and Kumar, Anil and Srivastava, A. K. and Dhar, Ajay (2018) Significant enhancement in thermoelectric performance of nanostructured higher manganese silicides synthesized employing a melt spinning technique. Nanoscale, 10 (4). pp. 1970-1977. ISSN 2040-3364 |
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| Relation |
http://npl.csircentral.net/3945/
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