Thermoelectric Transport in Ru_{2}TiSi Full-Heusler Compounds

Heusler compounds with six valence electrons per atom have attracted interest as thermoelectric materials owing to their semimetallic and semiconducting properties. Here, we theoretically and experimentally investigate electronic transport in Ru_{2}TiSi-based full-Heuslers. We show that electronic t...

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Bibliographic Details
Main Authors: Fabian Garmroudi, Michael Parzer, Takao Mori, Andrej Pustogow, Ernst Bauer
Format: Article
Language:English
Published: American Physical Society 2025-03-01
Series:PRX Energy
Online Access:http://doi.org/10.1103/PRXEnergy.4.013010
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Summary:Heusler compounds with six valence electrons per atom have attracted interest as thermoelectric materials owing to their semimetallic and semiconducting properties. Here, we theoretically and experimentally investigate electronic transport in Ru_{2}TiSi-based full-Heuslers. We show that electronic transport in this system can be well captured by a two-parabolic-band model. The larger band gap of Ru_{2}TiSi promises a higher thermoelectric performance, compared to its isovalent family member Fe_{2}VAl, which has been studied as a thermoelectric material for over two decades. Additionally, we identify p-type Ru_{2}TiSi as far more efficient than previously studied n-type compounds and demonstrate that this can be traced back to much lighter and more mobile holes originating from dispersive valence bands. Our findings suggest that an exceptionally high dimensionless figure of merit zT>1 can be realized in these p-type compounds around 700 K upon proper reduction of the lattice thermal conductivity, e.g., by substituting Zr or Hf for Ti.
ISSN:2768-5608