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
Physikalische Chemie
Schlagwörter
ASJC Scopus Sachgebiete
, , , ,
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