Thermoelectric properties enhancement of Ba0·2Co4Sb12 through dispersion of GaSb inclusions

Ghosh, S and Shankar, G and Karati, A and Rogl, G and Rogl, P and Bauer, E and Murty, BS and Suwas, S and Chandra Mallik, R (2021) Thermoelectric properties enhancement of Ba0·2Co4Sb12 through dispersion of GaSb inclusions. In: Physica B: Condensed Matter .

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Abstract

The combined effects of Ba-filling the voids and GaSb nanophase incorporation in the matrix of Co4Sb12 have been studied for thermoelectric properties. High energy ball-milling was used to disperse GaSb in Ba0·2Co4Sb12. A slight off-stoichiometry between Co and Sb generated CoSb2 and CoSb phases. Electron back-scattered diffraction showed nanocrystalline (50�200 nm) GaSb grains uniformly distributed on the matrix along with a few large grains (1�3 μm). The low electrical resistivity (�) of Ba0·2Co4Sb12 can be attributed to the +2 oxidation state of Ba. The increase in � of composites occurred due to the enhanced scattering of charge carriers at interfaces. No significant change in Seebeck coefficients was found in composites. The simultaneous effect of anharmonicity induced by Ba-filler in the voids and the enhanced interfaces between GaSb and the matrix reduced lattice thermal conductivity and brought about an improvement in zT from 0.75 to ~1.0 for (GaSb)0.4+Ba0·2Co4Sb12 at 773 K. © 2020 Elsevier B.V.

Item Type:	Journal Article
Publication:	Physica B: Condensed Matter
Publisher:	Elsevier B.V.
Additional Information:	The copyright of this article belongs to Elsevier B.V.
Keywords:	Ball milling; Barium compounds; Carrier mobility; III-V semiconductors; Nanocrystals; Semiconducting antimony compounds; Thermoelectric equipment; Thermoelectricity, Combined effect; Electron back-scattered diffraction; Enhanced scattering; High-energy ball milling; Lattice thermal conductivity; Nanocrystallines; Simultaneous effects; Thermoelectric properties, Gallium compounds
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Physical & Mathematical Sciences > Physics
Date Deposited:	05 Mar 2021 09:24
Last Modified:	05 Mar 2021 09:24
URI:	http://eprints.iisc.ac.in/id/eprint/68120

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