The intrinsic disorder related alloy scattering in ZrNiSn half-Heusler thermoelectric materials

Hanhui Xie, Heng Wang, Chenguang Fu, Yintu Liu, G. Jeffrey Snyder, Xinbing Zhao, Tiejun Zhu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

141 Scopus citations

Abstract

The intrinsic structural disorder dramatically affects the thermal and electronic transport in semiconductors. Although normally considered an ordered compound, the half-Heusler ZrNiSn displays many transport characteristics of a disordered alloy. Similar to the (Zr, Hf)NiSn based solid solutions, the unsubstituted ZrNiSn compound also exhibits charge transport dominated by alloy scattering, as demonstrated in this work. The unexpected charge transport, even in ZrNiSn which is normally considered fully ordered, can be explained by the Ni partially filling interstitial sites in this half-Heusler system. The influence of the disordering and defects in crystal structure on the electron transport process has also been quantitatively analyzed in ZrNiSn1-xSbxwith carrier concentration nH ranging from 5.0 × 1019 to 2.3 × 1021 cm-3 by changing Sb dopant content. The optimized carrier concentration nH ≈ 3-4 × 1020 cm-2 results in ZT ≈ 0.8 at 875K. This work suggests that MNiSn (M = Hf, Zr, Ti) and perhaps most other half-Heusler thermoelectric materials should be considered highly disordered especially when trying to understand the electronic and phonon structure and transport features.

Original languageEnglish (US)
Article number6888
JournalScientific reports
Volume4
DOIs
StatePublished - Nov 3 2014

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'The intrinsic disorder related alloy scattering in ZrNiSn half-Heusler thermoelectric materials'. Together they form a unique fingerprint.

Cite this