Thermoelectric properties and Kondo transition in the pseudo-gap metals TiNiSi and TiNiGe
Abstract
Materials with the TiNiSi structure have recently been highlighted as potential thermoelectric materials. Here we report the thermoelectric properties of TiNiX (X = Si and Ge). Both materials behave as defective metals or heavily doped degenerate semiconductors. Room temperature Seebeck coefficients are -45 μV K-1 (Si) and -20 μV K-1 (Ge) with electrical resistivities of 0.5-1 mΩ cm. The lattice thermal conductivities are 8 W m-1 K-1 (Si) and 6 W m-1 K-1 (Ge) at 360 K, which is promising in the absence of alloying. The calculated power factors and figures of merit remain small, with the largest S2/ρ = 0.17 mW m-1 K-2 and peak zT = 5 × 10-3 seen in TiNiSi near 300 K. Both compositions show Kondo behaviour at low-temperatures, linked to the emergence of local moment magnetism, and have substantial magnetoresistance effects at 2 K. This work provides property characterisation for two members of this large class of intermetallic materials.
Citation
Downie , R A , Kennedy , B , Biswas , R , Smith , R & Bos , J-W G 2023 , ' Thermoelectric properties and Kondo transition in the pseudo-gap metals TiNiSi and TiNiGe ' , Zeitschrift für Anorganische und Allgemeine Chemie , vol. 649 , no. 14 , e202300055 . https://doi.org/10.1002/zaac.202300055
Publication
Zeitschrift für Anorganische und Allgemeine Chemie
Status
Peer reviewed
ISSN
0044-2313Type
Journal article
Rights
Copyright © 2023 The Authors. Zeitschrift für anorganische und allgemeine Chemie published by Wiley-VCH GmbH This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Description
Funding: Engineering and Physical Sciences Research Council EP/J000884/1, EP/W037300/1 (RAD, BFK).Collections
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