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arXiv · 1801.08966

Stoichiometric and off-stoichiometric full Heusler $\mathbf {Fe_2V_{1-x}W_xAl} $ thermoelectric systems

B. Hinterleitner·P. Fuchs·J. Rehak·S. Steiner·M. Kishimoto·R. Moser·R. Podloucky·E. Bauer
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Abstract

A series of full-Heusler alloys, $\rm Fe_2V_{1-x}W_xAl$, $0 \leq x \leq 0.2$, was prepared, characterized and relevant physical properties to account for the thermoelectric performance were studied in a wide temperature range. Additionally, off-stoichiometric samples with similar compositions have been included, and a 10~\% improvement of the thermoelectric figure of merit was obtained. The V/W substitution causes i) a change of the main carrier type, from holes to electrons as evidenced from Seebeck and Hall measurements and ii) a substantial reduction of the lattice thermal conductivity due to a creation of lattice disorder by means of a distinct different mass and metallic radius upon the V/W substitution. Moreover $ZT$ values above 0.2 have been obtained. A microscopic understanding of the experimental data observed is revealed from ab-initio calculations of the electronic and phononic structure.

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B. Hinterleitner, P. Fuchs, J. Rehak, S. Steiner, M. Kishimoto, R. Moser, R. Podloucky, E. Bauer. 2018-01-26. Stoichiometric and off-stoichiometric full Heusler $\mathbf {Fe_2V_{1-x}W_xAl} $ thermoelectric systems. https://doi.org/10.1103/physrevb.102.075117

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