2023/06/25 by Mohd Zeeshan, Zeeshan, Mohd, Chandan Kumar Vishwakarma +3
Engineering · Materials Science · #Advanced Thermoelectric Materials and Devices #FOS: Physical sciences #Heusler alloys: electronic and magnetic properties #Intermetallics and Advanced Alloy Properties #Materials Science (cond-mat.mtrl-sci)
paper · pdf · doi:10.48550/arxiv.2306.14234
openalex publication_date 2023/06/25 · openalex created_date 2023/06/28 · openalex updated_date 2026/07/28
High lattice thermal conductivity in half-Heusler alloys has been the major bottleneck in thermoelectric applications. Disordered half-Heusler alloys could be a plausible alternative to this predicament. In this paper, utilizing first-principles simulations, we have demonstrated the low lattice thermal conductivity in two such phases, NbFe0.5Ni0.5Sn and TaFe0.5Ni0.5Sn, in comparison to well-known half-Heusler alloy TiCoSb. We trace the low thermal conductivity to their short phonon lifetime, originating from the interaction among acoustic and low-lying optical phonons. We recommend nanostructuring as an effective route in further diminishing the lattice thermal conductivity. We further predict that these alloys can be best used in the temperature range 400-600~K and carrier concentration of less than 1021 carriers cm-3. We found ∼35% and ∼17% enhancement in ZT for NbFe0.5Ni0.5Sn and TaFe0.5Ni0.5Sn, respectively, as compared to TiCoSb. We are optimistic of the findings and believe these materials would attract experimental investigations.