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

0494145 - ÚFM 2019 RIV GB eng J - Článek v odborném periodiku
Rogl, G. - Buršík, Jiří - Grytsiv, A. - Puchegger, S. - Soprunyuk, V. - Schranz, W. - Yan, X. - Bauer, E. - Roo, R.
Nanostructuring as a tool to adjust thermal expansion in high ZT skutterudites.
Acta Materialia. Roč. 145, FEB (2018), s. 359-368. ISSN 1359-6454. E-ISSN 1873-2453
Grant CEP: GA ČR(CZ) GA17-12844S
Institucionální podpora: RVO:68081723
Klíčová slova: dispersion strengthening * mechanical properties * nano composite
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 7.293, rok: 2018

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.
Trvalý link: http://hdl.handle.net/11104/0287449