Issue 44, 2015

Morphological effects on the thermoelectric properties of Ti0.3Zr0.35Hf0.35Ni1+δSn alloys following phase separation

Abstract

Thermoelectrics are known as one of the emerging renewable power generation technologies. Half-Heusler based semiconducting intermetallic compounds show high potential as thermoelectric materials due to the abundance of their elements in nature, their high mechanical and chemical stability, and their favorable electronic properties. Their main limitation lies in their high lattice thermal conductivity, κl. In the current research, the potential of κl reduction due to generation of composites based on phase separation of off-stoichiometric Ti0.3Zr0.35Hf0.35Ni1+δSn alloys into half- and full-Heusler composites was investigated. Due to the strong metallic nature of the full-Heusler phase, its electronic effect on the thermoelectric transport properties under various morphological and compositional conditions was analyzed by the general effective media (GEM) approach. It was shown that although a major κl reduction of up to ∼37% was associated with phonon scattering by the embedded full Heusler phase, the electronic properties for the parallel-like alignment of this phase, following arc melting and spark plasma sintering, deteriorated with increase of the relative amount of this phase. Therefore a maximal ZT enhancement of ∼41%, compared to the uni-phase HH stoichiometric composition, was obtained for the minimal (δ = 0.01) deviation of the stoichiometry examined, corresponding to the minimal relative amount of the scattered FH phase inside the HH matrix.

Graphical abstract: Morphological effects on the thermoelectric properties of Ti0.3Zr0.35Hf0.35Ni1+δSn alloys following phase separation

Article information

Article type
Paper
Submitted
07 Okt. 2015
Accepted
09 Okt. 2015
First published
12 Okt. 2015

J. Mater. Chem. C, 2015,3, 11653-11659

Morphological effects on the thermoelectric properties of Ti0.3Zr0.35Hf0.35Ni1+δSn alloys following phase separation

O. Appel, T. Zilber, S. Kalabukhov, O. Beeri and Y. Gelbstein, J. Mater. Chem. C, 2015, 3, 11653 DOI: 10.1039/C5TC03214H

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