High-Pressure Torsion to Improve Thermoelectric Efficiency of Clathrates?

Autor(en)

Xinlin Yan, Matthias Falmbigl, Gerda Rogl, Andrij Grytsiv, A. Prokofiev, Ernst Bauer, Peter Franz Rogl, Michael Zehetbauer, Silke Paschen

Abstrakt

High-pressure torsion (HPT), as a technique to produce severe plastic deformation, has been proven effective to improve the thermoelectric performance of skutterudites. In this report, we present microstructural and thermoelectric properties of the clathrate Ba8Cu3.5Ge41In1.5 processed by HPT. The sample was synthesized from high-purity elements, subsequently annealed, ball milled, and hot pressed, and finally subject to HPT. Compared with the ball-milled and hot-pressed sample, the HPT-processed sample has higher electrical resistivity and Seebeck coefficient, and lower thermal conductivity, electron concentration, and mobility, which is attributed to the reduced grain size and increased density of dislocations, point defects, and cracks. No essential improvement of the dimensionless thermoelectric figure of merit is observed in the investigated temperature range, questioning the universal versatility of this technique for improvement of thermoelectric materials.

Organisation(en)

Institut für Physikalische Chemie, Physik Nanostrukturierter Materialien

Externe Organisation(en)

Technische Universität Wien

Journal

Journal of Electronic Materials

Band

42

Seiten

1330-1334

Anzahl der Seiten

5

ISSN

0361-5235

DOI

https://doi.org/10.1007/s11664-012-2440-8

Publikationsdatum

2013

Peer-reviewed

Ja

ÖFOS 2012

104017 Physikalische Chemie, 210006 Nanotechnologie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/a1adf718-7813-4696-9d3b-d078b98d7e91