Issue 40, 2015

Fine tuning of thermoelectric performance in phase-separated half-Heusler compounds

Abstract

Two successful recipes to enhance the thermoelectric performance, namely carrier concentration optimization and reduction of thermal conductivity, have been combined and applied to the p-type (Ti/Zr/Hf)CoSb1−xSnx system. An intrinsic micrometer-scale phase separation increases the phonon scattering and reduces the lattice thermal conductivity. A substitution of 15% Sb by Sn optimizes the electronic properties. Starting from this, further improvement of the thermoelectric properties has been achieved by a fine tuning of the Ti to Hf ratio. The microstructuring of the samples was studied in detail with high-resolution synchrotron powder X-ray diffraction and element mapping electron microscopy. Linking the structural with the thermoelectric properties, a record thermoelectric figure of merit for p-type half-Heusler compounds of ZT ≈ 1.2 at 710 °C in Ti0.25Hf0.75CoSb0.85Sn0.15 was achieved. The phase separation approach can form a significant alternative to nanostructuring processing, saving time, energy consumption and increasing the thermoelectric efficiency.

Graphical abstract: Fine tuning of thermoelectric performance in phase-separated half-Heusler compounds

Article information

Article type
Paper
Submitted
28 апр. 2015
Accepted
18 јун. 2015
First published
23 јун. 2015

J. Mater. Chem. C, 2015,3, 10409-10414

Author version available

Fine tuning of thermoelectric performance in phase-separated half-Heusler compounds

E. Rausch, B. Balke, J. M. Stahlhofen, S. Ouardi, U. Burkhardt and C. Felser, J. Mater. Chem. C, 2015, 3, 10409 DOI: 10.1039/C5TC01196E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements