Bathula, Sivaiah and Jayasimhadri, M. and Jayasimhadri, M. and Kumar, Anil and Srivastava, A. K. and Dhar, Ajay (2017) Enhancement in thermoelectric performance of SiGe nanoalloys dispersed with SiC nanoparticles. Physical Chemistry Chemical Physics, 19. pp. 25180-25185. ISSN 1463-9076

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Abstract

SiGe is one of the most widely used thermoelectric materials for radioisotope thermoelectric generator applications for harnessing waste-heat at high temperatures. In the present study, we report a simple experimental strategy for enhancing the thermoelectric and mechanical properties of n-type SiGe nanoalloys by dispersing SiC nanoparticles in a SiGe nanoalloy matrix. This strategy yielded a high value of figure-of-merit (ZT) of similar to 1.7 at 900 degrees C in the SiGe/SiC nanocomposite, which is nearly twice that reported for its pristine bulk counterpart and similar to 15% higher than that of pristine SiGe nanoalloys. This significant enhancement in the ZT primarily originates from a reduction in the lattice thermal conductivity, owing to a high density of nano-scale interfaces, lattice-scale modulations and mass fluctuations, which lead to extensive scattering of heat-carrying phonons. The dispersion of SiC nanoparticles also significantly enhances the mechanical properties of the resulting SiGe/SiC nanocomposite, including fracture toughness and hardness. The enhancement in the thermoelectric and mechanical properties of the SiGe/SiC nanocomposites has been correlated with their microstructural features, elucidated employing X-ray diffraction, and scanning and transmission electron microscopy.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Royal Society of Chemistry.
Subjects:	Chemistry > Physical Chemistry
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	06 Sep 2018 11:19
Last Modified:	06 Sep 2018 11:19
URI:	http://npl.csircentral.net/id/eprint/2703

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