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

2015/02/11 by Elisabeth Rausch, Siham Ouardi, Rausch, Elisabeth +9
Materials Science · Physics and Astronomy · #Advanced Thermoelectric Materials and Devices #FOS: Physical sciences #Heusler alloys: electronic and magnetic properties #Materials Science (cond-mat.mtrl-sci) #Topological Materials and Phenomena #cond-mat.mtrl-sci

paper · pdf · doi:10.48550/arxiv.1502.03336

13 pages, 6 figures, 1 table

arxiv created 2015/02/11 · openalex publication_date 2015/02/11 · arxiv updated 2015/02/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

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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