Publikationen
Thermoelectric Half-Heusler compounds TaFeSb and Ta <sub>1-x</sub> Ti <sub>x</sub> FeSb (0 ≤ x ≤ 0.11): Formation and physical properties
- Autor(en)
- A. Grytsiv, V. V. Romaka, N. Watson, G. Rogl, H. Michor, B. Hinterleitner, S. Puchegger, E. Bauer, P. Rogl
- Abstrakt
-
We report on the formation, physical-chemical, as well as elastic and mechanical properties of the novel Half-Heusler (HH) compound TaFeSb that forms during a solid-state reaction from TaSb
2
and TaFe
2
in the temperature range between 800 and 850 °C. TaFeSb behaves as a semiconductor, and changes the conductivity type either on temperature or composition. Transport properties of TaFeSb and Ta
1-x
Ti
x
FeSb (0 ≤ x ≤ 0.11) were measured in the temperature range from 4.2 to 823 K, and the effect of titanium on thermoelectric and mechanical properties of Ta
1-x
Ti
x
FeSb was investigated. The Ta/Ti substitution results in a significant increase of the thermoelectric power factor to exciting values of above 6 mW/m⋅K
2
. In combination with a suppressed phonon thermal conductivity, due to a unique role of Ti, an enhanced figure of merit, ZT
900K
=1.0 (for Ta
0.94
Ti
0.06
FeSb) is obtained, close to the highest values reported for Hf-free p-type HH-systems. In addition, experimental results obtained in this study are discussed and analyzed in the context of ab-initio Density Functional Theory (DFT) calculations.
- Organisation(en)
- Institut für Materialchemie, Fakultätszentrum für Nanostrukturforschung
- Externe Organisation(en)
- Christian Doppler Laboratory for Thermoelectricity, Lviv Polytechnic National University, Technische Universität Wien, Universität Wien
- Journal
- Intermetallics
- Band
- 111
- ISSN
- 0966-9795
- DOI
- https://doi.org/10.1016/j.intermet.2019.04.011
- Publikationsdatum
- 08-2019
- Peer-reviewed
- Ja
- ÖFOS 2012
- 104017 Physikalische Chemie
- Schlagwörter
- ASJC Scopus Sachgebiete
- Chemistry(all), Mechanics of Materials, Mechanical Engineering, Metals and Alloys, Materials Chemistry
- Link zum Portal
- https://ucris.univie.ac.at/portal/de/publications/thermoelectric-halfheusler-compounds-tafesb-and-ta-1x-ti-x-fesb-0--x--011-formation-and-physical-properties(8f32964b-186b-4873-a511-3c4a38c3d837).html