Thermoelectric properties of a high entropy half-Heusler alloy processed by a fast powder metallurgy route

Karati, A and Mishra, SR and Ghosh, S and Mallik, RC and Shabadi, R and Ramanujan, RV and Yadav, SK and Murty, BS and Varadaraju, UV (2022) Thermoelectric properties of a high entropy half-Heusler alloy processed by a fast powder metallurgy route. In: Journal of Alloys and Compounds, 924 .

PDF jou_all_com_924_2022.pdf - Published Version Restricted to Registered users only Download (13MB) | Request a copy

Abstract

A half-Heusler (HH) type high entropy alloy (HEA) Ti2NiCoSnSb has been synthesized by a fast powder metallurgy route for the first time. Mechanical alloying (MA) by wet milling produced a powder with a minor fraction of the HH phase. The dry milling route resulted in the desired single-phase HH material. Consolidation of the nanocrystalline mechanically alloyed (MA) powder by spark plasma sintering (SPS) resulted in a majority HH phase. Interestingly, the nanocrystalline alloy exhibited simultaneous enhancement in the Seebeck coefficient and electrical conductivity, with a maximum ZT of 0.13 at 973 K observed for the dry milled alloy. The band structure obtained by density functional theory (DFT) was in good agreement with the ultraviolet-visible-near infrared (UV-Vis-NIR) absorption spectroscopy results. The DFT calculations and microstructural analysis suggest that phase separation strongly influenced the thermoelectric properties. The band structure calculations provided a good rationale for the phase evolution and thermoelectric properties.

Item Type:	Journal Article
Publication:	Journal of Alloys and Compounds
Publisher:	Elsevier Ltd
Additional Information:	The copyright for this article belongs to the Elsevier Ltd.
Keywords:	Electronic band structure; Half-Heusler; High entropy alloy; Mechanical alloying; Thermoelectric material
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	03 Sep 2022 05:05
Last Modified:	03 Sep 2022 05:05
URI:	https://eprints.iisc.ac.in/id/eprint/76401

Actions (login required)

View Item