2025/09/02 by Fabian Garmroudi, Illia Serhiienko, Garmroudi, Fabian +11
Materials Science · #Advanced Thermoelectric Materials and Devices #FOS: Physical sciences #Heusler alloys: electronic and magnetic properties #MXene and MAX Phase Materials #Materials Science (cond-mat.mtrl-sci)
paper · pdf · doi:10.48550/arxiv.2509.02765
openalex publication_date 2025/09/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Heusler compounds have emerged as important thermoelectric materials due to their combination of promising electronic transport properties, mechanical robustness and chemical stability -- key aspects for practical device integration. While a wide range of XYZ-type half-Heusler compounds have been studied for high-temperature applications, X2YZ-type full-Heuslers, often characterized by narrower band gaps, may offer potential advantages at different temperature regimes but remain less explored. In this work, we report the discovery of p-type Ru2Ti1-xHfxSi full-Heusler thermoelectrics, exhibiting a high figure of merit zT ∼ 0.7 over a broad range of temperatures 700-1000 K. These results not only represent the largest values known to date among full-Heusler materials but confirm earlier theoretical predictions that p-type Ru2TiSi systems would be superior to their n-type counterparts. Moreover, using a two-band model, we unveil electronic structure changes induced by the Hf substitution at the Ti site and outline strategies to further improve zT up to zT > 1. Our findings highlight the untapped potential of new semiconducting full-Heusler phases and the crucial need for continued exploration of this rich materials class for thermoelectric applications.