Half-Heusler-like compounds with wide continuous compositions and tunable p- to n-type semiconducting thermoelectrics.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35013264.
- Also identified by DOI 10.1038/s41467-021-27795-3 and PMC identifier 8748599.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Half-Heusler and full-Heusler compounds were considered as independent phases with a natural composition gap. Here we report the discovery of TiRu<sub>1+x</sub>Sb (x = 0.15 ~ 1.0) solid solution with wide homogeneity range and tunable p- to n-type semiconducting thermoelectrics, which bridges the composition gap between half- and full-Heusler phases. At the high-Ru end, strange glass-like thermal transport behavior with unusually low lattice thermal conductivity (~1.65 Wm<sup>-1</sup>K<sup>-1</sup> at 340 K) is observed for TiRu<sub>1.8</sub>Sb, being the lowest among reported half-Heusler phases. In the composition range of 0.15 < x < 0.50, TiRu<sub>1+x</sub>Sb shows abnormal semiconducting behaviors because tunning Ru composition results in band structure change and carrier-type variation simultaneously, which seemingly correlates with the localized d electrons. This work reveals the possibility of designing fascinating half-Heusler-like materials by manipulating the tetrahedral site occupancy, and also demonstrates the potential of tuning crystal and electronic structures simultaneously to realize intriguing physical properties.