Vacancy defect control of colossal thermopower in FeSb2
Iron diantimonide is a material with the highest known thermoelectric power. By combining scanning transmission electron microscopic study with electronic transport neutron, X-ray scattering, and first principle calculation, we identify atomic defects that control colossal thermopower magnitude and nanoprecipitate clusters with Sb vacancy ordering, which induce additional phonon scattering and substantially reduce thermal conductivity. Defects are found to cause rather weak but important monoclinic distortion of the unit cell Pnnm → Pm. The absence of Sb along  for high defect concentration forms conducting path due to Fe d orbital overlap. The connection between atomic defect anisotropy and colossal thermopower in FeSb2 paves the way for the understanding and tailoring of giant thermopower in related materials.
© 2021 The Authors. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
Du, Qianheng, Lijun Wu, Huibo Cao, Chang-Jong Kang, Christie Nelson, Gheorghe Lucian Pascut, Tiglet Besara et al. "Vacancy defect control of colossal thermopower in FeSb 2." npj Quantum Materials 6, no. 1 (2021): 1-7.
npj Quantum Materials