Nanostructuring as a tool to adjust thermal expansion in high ZT skutterudites

Autor(en)

G. Rogl, J. Bursik, A. Grytsiv, S. Puchegger, V. Soprunyuk, W. Schranz, X. Yan, E. Bauer, Peter Franz Rogl

Abstrakt

Although filled skutterudites have a high figure of merit, ZT, it is still an aim to further improve their thermoelectric behavior. One successful route is to homogeneously disperse nanoparticles into the skutterudite matrix and thereby to reduce the lattice thermal conductivity without disturbing the electrical conductivity and the Seebeck coefficient. In this work Ta0.8Zr0.2B was dispersed into n-type (Mm,Sm)(y)Co4Sb12 powder by ball-milling or high energy ball-milling prior to hot-pressing. Structural and physical properties, covering also the low temperature range, were studied and compared with the recently investigated impact of nano Ta0.8Zr0.2B on p-type skutterudites. ZT was enhanced by 16%.

As for thermoelectric applications good mechanical properties are important, we investigated the influence of Ta0.8Zr0.2B nanoparticles, added to (Mm,Sm)(y)Co4Sb12, on the hardness, elastic moduli and fracture toughness and found an enhancement of all three mechanical properties. It is well known that p-type skutterudites generally have a higher thermal expansion coefficient than their n-type counterpart. We show that dispersed borides in both n-type (Mm,Sm)(y)Co4Sb12 and p-type DD0.7Fe3CoSb12 can level out this discrepancy. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Organisation(en)

Institut für Materialchemie, Fakultätszentrum für Nanostrukturforschung, Physik Funktioneller Materialien

Externe Organisation(en)

Czech Academy of Sciences, Technische Universität Wien

Journal

Acta Materialia

Band

145

Seiten

359-368

Anzahl der Seiten

10

ISSN

1359-6454

DOI

https://doi.org/10.1016/j.actamat.2017.12.001

Publikationsdatum

02-2018

Peer-reviewed

Ja

ÖFOS 2012

104011 Materialchemie, 104017 Physikalische Chemie

Schlagwörter

Link zum Portal

https://ucris.univie.ac.at/portal/de/publications/nanostructuring-as-a-tool-to-adjust-thermal-expansion-in-high-zt-skutterudites(d136012e-89d4-4262-8558-023219a35592).html