Effect of Al-doping on suppression of thermal conductivity in Si dispersed beta-FeSi2

Rajasekar, P and Umarji, Arun M (2017) Effect of Al-doping on suppression of thermal conductivity in Si dispersed beta-FeSi2. In: INTERMETALLICS, 89 . pp. 57-64.

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Abstract

Silicon dispersed beta-FeSi2 with different aluminium concentrations are synthesized using eutectoid decomposition of alpha-Fe(2)Si(5-x)A(lx) ( <= x <= 0.1). Phase fractions, microstructure and thermoelectric properties of the above compositions have been investigated. Al-doping in Si dispersed beta-FeSi2 results in increased hole-carrier concentration thereby enhancing the electrical conductivity without compromising the Seebeck coefficient. This results in maximum power factor value of 4.7 mu Wcm(-1) K-2 at 773 K for the sample with x = 0.1 which is significantly higher than that of an undoped sample. The thermal conductivity of the samples was fitted with the Debye-Callaway model to understand the various scattering processes involved. The analysis shows that an increased point defect scattering of phonons with Al-doping in addition to scattering by Si/beta-FeSi2 interface lowers the thermal conductivity significantly.

Item Type:	Journal Article
Publication:	INTERMETALLICS
Additional Information:	Copy right for this article belongs to the ELSEVIER SCI LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	01 Sep 2017 04:57
Last Modified:	01 Sep 2017 04:57
URI:	http://eprints.iisc.ac.in/id/eprint/57682

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