Thermoelectric transport in Ru$_2$TiSi full-Heusler compounds

Fuente: arXiv
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Main Authors: Garmroudi, Fabian, Parzer, Michael, Mori, Takao, Pustogow, Andrej, Bauer, Ernst
Format: Preprint
Published: 2024
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author Garmroudi, Fabian
Parzer, Michael
Mori, Takao
Pustogow, Andrej
Bauer, Ernst
author_facet Garmroudi, Fabian
Parzer, Michael
Mori, Takao
Pustogow, Andrej
Bauer, Ernst
contents 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 demonstrate 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.
format Preprint
id arxiv_https___arxiv_org_abs_2412_06039
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Thermoelectric transport in Ru$_2$TiSi full-Heusler compounds
Garmroudi, Fabian
Parzer, Michael
Mori, Takao
Pustogow, Andrej
Bauer, Ernst
Materials Science
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 demonstrate 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.
title Thermoelectric transport in Ru$_2$TiSi full-Heusler compounds
topic Materials Science
url https://arxiv.org/abs/2412.06039