Thermoelectric properties and Kondo transition in the pseudo‐gap metals TiNiSi and TiNiGe

Autor: Downie, Ruth A., Kennedy, Blair, Biswas, Rajan, Smith, Ronald, Bos, Jan-Willem Gezienes
Přispěvatelé: University of St Andrews. School of Chemistry
Rok vydání: 2023
Předmět:
Zdroj: Zeitschrift für anorganische und allgemeine Chemie.
ISSN: 1521-3749
0044-2313
Popis: Funding: Engineering and Physical Sciences Research Council EP/J000884/1, EP/W037300/1 (RAD, BFK). 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. Publisher PDF
Databáze: OpenAIRE
Externí odkaz: