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RESEARCH PRODUCT
Long-term stability of phase-separated half-Heusler compounds
Claudia FelserJulia KrezMarkus SchwindSusanne SelleBenjamin BalkeThomas HöcheWilfried HermesSiham Ouardisubject
Thermal conductivityChemistrySeebeck coefficientPhase (matter)Thermoelectric effectAnalytical chemistryGeneral Physics and AstronomyFigure of meritPhysical and Theoretical ChemistryMicrostructureStability (probability)description
Half-Heusler (HH) compounds have shown high figure of merit up to 1.5. Here, we address the long-term stability of n- and p-type HH materials. For this purpose, we investigated HH materials based on the Ti0.3Zr0.35Hf0.35NiSn-system after 500 cycles (1700 h) from 373 to 873 K. Both compounds exhibit a maximum Seebeck coefficient of |α|≈ 210 μV K(-1) and a phase separation into two HH phases. The dendritic microstructure is temperature resistant and upon cycling the changes in the microstructure are so marginal that the low thermal conductivity values (κ4 W m(-1) K(-1)) could be maintained. Our results emphasize that phase-separated HH compounds are suitable low cost materials and can lead to enhanced thermoelectric efficiencies beyond the set benchmark for industrial applications.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2015-10-22 |