Stoichiometric and off-stoichiometric full Heusler Fe2V1−xWxAl thermoelectric systems
| Autor: | P. Fuchs, Robert Svagera, J. Rehak, M. Kishimoto, Fabian Garmroudi, M. Waas, E. Bauer, R. Moser, Soner Steiner, Michael Parzer, Raimund Podloucky, B. Hinterleitner |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Condensed matter physics 02 engineering and technology Electron Atmospheric temperature range 021001 nanoscience & nanotechnology 01 natural sciences Metal Ab initio quantum chemistry methods visual_art Lattice (order) 0103 physical sciences Thermoelectric effect visual_art.visual_art_medium Thin film 010306 general physics 0210 nano-technology Stoichiometry |
| Zdroj: | Physical Review B. 102 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.102.075117 |
| Popis: | A series of full Heusler alloys, ${\text{Fe}}_{2}{\text{V}}_{1\ensuremath{-}x}{\text{W}}_{x}\text{Al}$, $0\ensuremath{\le}x\ensuremath{\le}0.2$, was prepared and 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. This series of alloys constitutes the basis for thin film systems, which have recently been found to exhibit $ZT$ values beyond those reported so far in the literature. |
| Databáze: | OpenAIRE |
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