Nanostructuration via solid state transformation as a strategy for improving the thermoelectric efficiency of PbTe alloys

Gorsse, S and Bellanger, P and Brechet, Y and Sellier, E and Umarji, A and Ail, Ujwala and Decourt, R (2011) Nanostructuration via solid state transformation as a strategy for improving the thermoelectric efficiency of PbTe alloys. In: Acta Materialia, 59 (19). pp. 7425-7437.

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Abstract

The approach taken in this paper in order to modify the scattering features of electrons and phonons and improve the figure of merit (ZT) of thermoelectric PbTe is to alter the microstructure at constant chemistry. A lamellar pattern of PbTe/GeTe at the nano- and microscale was produced in Pb(0.36)Ge(0.64)Te alloy by the diffusional decomposition of a supersaturated solid solution. The mechanism of nanostructuration is most likely a discontinuous spinodal decomposition. A simple model relating the interface velocity to the observed lamellar spacing is proposed. The effects of nanostructuration in Pb(0.36)Ge(0.64)Te alloy on the electrical and thermal conductivity, thermopower and ZT were investigated. It was shown that nanostructuration through the formation of a lamellar pattern of PbTe/GeTe is unlikely to provide a significant improvement due to the occurrence of discontinuous coarsening. However, the present study allows an analysis of possible strategies to improve thermoelectric materials via optimal design of the microstructure and optimized heat treatment. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	Acta Materialia
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Nanocomposite;Aging;Electrical resistivity/conductivity; Spinodal decomposition;Modelling
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	29 Nov 2011 09:46
Last Modified:	18 Feb 2019 11:05
URI:	http://eprints.iisc.ac.in/id/eprint/42408

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