Thermoelectric performance of mischmetal skutterudites MmyFe4-xCoxSb12 at elevated temperatures

Autor(en)

Long Zhang, Andrij Grytsiv, Michael Kerber, Peter Franz Rogl, Ernst Bauer, Michael Zehetbauer

Abstrakt

Thermoelectric behaviour was studied for MmyFe4-xCoxSb12 with x = 0 and 1 (Mm is mischmetal) within the temperature range from 300 K to 800 K and was compared with data for corresponding CeyFe4-xCoxSb12. No decrease of thermal conductivity at high temperatures was observed changing from a single atom filler (Ce) to a multi-element filler (Mm). The electrical resistivity of MmyFe4-xCoxSb12 was found to be lower than or similar to that of CeyFe4-xCoxSb12. Accordingly the figure of merit for MmFe3CoSb12 exceeds 1 at temperatures above 600 K. The influence of several parameters such as impurity phases and grain size on the thermoelectric performance of MmyFe4-xCoxSb12 was investigated. FeSb2 and Sb have little effect on the figure of merit whilst the presence of MmSb2 and oxides reduces the thermoelectric performance, when these phases are segregated at the grain boundaries. The decrease of the crystallite size from micro scale (20–100 ?m) to nano-scale (100–300 nm) in all cases improves the figure of merit by about 20%. Dislocations have no influence on ZT since the dislocation density after hot pressing is as low as 1012 m-2.

Organisation(en)

Physik Nanostrukturierter Materialien, Institut für Physikalische Chemie

Externe Organisation(en)

Technische Universität Wien

Journal

Journal of Alloys and Compounds

Band

490

Seiten

19-25

Anzahl der Seiten

7

ISSN

0925-8388

DOI

https://doi.org/10.1016/j.jallcom.2009.10.033

Publikationsdatum

2010

Peer-reviewed

Ja

ÖFOS 2012

103023 Polymerphysik, 210006 Nanotechnologie, 103018 Materialphysik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/0f75e0a8-fecb-4fa1-b9b1-3deaa4f9c035