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arXiv · 1502.03336

High thermoelectric figure of merit in p-type Half-Heuslers by intrinsic phase separation

Elisabeth Rausch·Siham Ouardi·Ulrich Burkhardt·Claudia Felser·Jana Marie Stahlhofen·Benjamin Balke
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Abstract

Improvements in the thermoelectric properties of Half-Heusler materials have been achieved by means of a micrometer-scale phase separation that increases the phonon scattering and reduces the lattice thermal conductivity. A detailed study of the p-type Half-Heusler compounds Ti(1-x)Hf(x)CoSb0.85Sn0.15 using high-resolution synchrotron powder X-ray diffraction and element mapping electron microscopy evidences the outstanding thermoelectric properties of this system. A combination of intrinsic phase separation and adjustment of the carrier concentration via Sn substitution is used to realize a record thermoelectric figure of merit for p-type Half-Heusler compounds of ZT around 1.15 at 710C in Ti0.25Hf0.75CoSb0.85Sn0.15. The phase separation approach can form a significant alternative to nanostructuring processing time, energy consumption and increasing the thermoelectric efficiency.

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Elisabeth Rausch, Siham Ouardi, Ulrich Burkhardt, Claudia Felser, Jana Marie Stahlhofen, Benjamin Balke. 2015-02-11. High thermoelectric figure of merit in p-type Half-Heuslers by intrinsic phase separation. https://arxiv.org/abs/1502.03336

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