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.
Original language | English |
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Article number | e202300055 |
Journal | Zeitschrift für anorganische und allgemeine Chemie |
Volume | 649 |
Issue number | 14 |
Early online date | 16 May 2023 |
DOIs | |
Publication status | Published - 17 Jul 2023 |
Keywords
- Kondo effect
- Thermoelectric materials
- TiNiSi structure
- intermetallic
ASJC Scopus subject areas
- Inorganic Chemistry