Abstract
Controlling the local structure of high-entropy materials offers a promising pathway to resolve the trade-off of electron and phonon transport behaviors, which unlocks their full potential in thermoelectric applications. Herein, utilizing time-of-flight neutron total scattering and advanced multiscale simulations, we unveil the intricate local structures spanning both short- and long-range scales in high-entropy chalcogenides AgMnPbSbTe4and AgMnGePbSbTe5, characterized by pronounced long-range cation disordering and well-defined short-range ordering. Notably, pair distribution function refinements revealed substantial discrepancies near 3 Å, unequivocally indicating significant local distortions from PbTe. Besides enhancing Pb-site asymmetry, the high-entropy strategy also triggers chemical bonding evolutions from purely ionic interactions in PbTe to mixed covalent-ionic features in AgMnPbSbTe4, and ultimately to more robust covalent-ionic interactions in AgMnGePbSbTe5. This transformation produces a 3-fold enhancement in electrical conductivity for AgMnGePbSbTe5relative to AgMnPbSbTe4, and an orders-of-magnitude improvement over PbTe. Due to the enhanced covalent character imparted by Ge–Te bonding and weakened local octahedral structural distortions with long-ranged scales, the lattice thermal conductivity of AgMnGePbSbTe5surpasses that of AgMnPbSbTe4across the entire temperature range. By optimizing high-entropy materials from the local chemical order, we achieve a maximum ZT of 1.66 at 750 K in pure AgMnGePbSbTe5, significantly outperforming intrinsic PbTe (∼ 0.26 at 720 K) and other PbTe-based composites. Our findings not only elucidate the underlying mechanisms governing the anomalously low thermal conductivity in high-entropy materials but also establish a correlation between local structural distortions and thermoelectric performance, thereby providing critical insights for the rational design of next-generation thermoelectric materials.
| Original language | English |
|---|---|
| Pages (from-to) | 41629-41638 |
| Number of pages | 10 |
| Journal | Journal of the American Chemical Society |
| Volume | 147 |
| Issue number | 45 |
| DOIs | |
| State | Published - Nov 12 2025 |
Funding
This work was financially supported by the National Key Research and Development Program of China (Grant Nos. 2021YFA1600700 and 2020YFA0406201). The authors acknowledged financial support from the financial support from Guangdong Basic and Applied Basic Research Foundation (Grant No. 2023A1515111190) and National Natural Science Foundation of China (Grant Nos. 12574027 and 12504029). Dr. Yuanpeng Zhang acknowledges the sponsor by Office of Basic Energy Sciences, US Department of Energy and the following funding is acknowledged: US Department of Energy, Office of Science (Contract No. DE-AC05-00OR22725). The calculations were performed at the CSNS Scientific Computing Platform of Institute of High Energy Physics of CAS and GBA Subcenter of National HEP Science Data Center (CSNS SC Platform of IHEP CAS & GBA Sub-Center of NHEPDC). We would like to express our gratitude to Luzhou Yu from the University of Ottawa and Ting Liu from the Spallation Neutron Source Science Center for their assistance in data organization.