Thermoelectric properties of Co4Sb12 with Bi2Te3 nanoinclusions

Ghosh, Sanyukta and Bisht, Anuj and Karati, Anirudha and Rogl, Gerda and Rogl, Peter and Murty, B S and Suwas, Satyam and Mallik, Ramesh Chandra (2018) Thermoelectric properties of Co4Sb12 with Bi2Te3 nanoinclusions. In: JOURNAL OF PHYSICS-CONDENSED MATTER, 30 (9).

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Abstract

The figure of merit (zT) of a thermoelectric material can be enhanced by incorporation of nanoinclusions into bulk material. The presence of bismuth telluride (Bi2Te3) nanoinclusions in Co4Sb12 leads to lower phonon thermal conductivity by introducing interfaces and defects; it enhances the average zT between 300-700 K. In the current study, Bi2Te3 nanoparticles were dispersed into bulk Co4Sb12 by ball-milling. The bulk was fabricated by spark plasma sintering. The presence of Bi2Te3 dispersion in Co4Sb12 was confirmed by x-ray diffraction, scanning electron microscopy, transmission electron microscopy and electron back scattered diffraction technique. Energy dispersive spectroscopy showed antimony (Sb) as an impurity phase for higher contents of Bi2Te3 in the sample. The Seebeck coefficient (S) and electrical conductivity (sigma) were measured in the temperature range of 350-673 K. The negative value of S indicates that most of the charge carriers were electrons. A decrease in S and increase in.. with Bi2Te3 content are due to the increased carrier concentration, as confirmed by Hall measurement. The thermal conductivity, measured between 423-673 K, decreased due to the increased phonon scattering at interfaces. A maximum zT of 0.17 was achieved at 523 K and it did not vary much throughout the temperature range. The experimental results of composites were compared by using effective medium theories.

Item Type:	Journal Article
Publication:	JOURNAL OF PHYSICS-CONDENSED MATTER
Publisher:	IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
Additional Information:	Copy right for the article belong to IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Physical & Mathematical Sciences > Physics
Date Deposited:	08 Mar 2018 19:09
Last Modified:	25 Aug 2022 05:50
URI:	https://eprints.iisc.ac.in/id/eprint/59104

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