Abstract
Negative thermal expansion (NTE) alloys possess great practical merit as thermal offsets for positive thermal expansion due to its metallic properties. However, achieving a large NTE with a wide temperature range remains a great challenge. Herein, a metallic framework-like material FeZr2 is found to exhibit a giant uniaxial (1D) NTE with a wide temperature range (93-1078 K, α¯l=−34.01×10−6K−1). Such uniaxial NTE is the strongest in all metal-based NTE materials. The direct experimental evidence and DFT calculations reveal that the origin of giant NTE is the couple with phonons, flexible framework-like structure, and soft bonds. Interestingly, the present metallic FeZr2 excites giant 1D NTE mainly driven by high-frequency optical branches. It is unlike the NTE in traditional framework materials, which are generally dominated by low energy acoustic branches. In the present study, a giant uniaxial NTE alloy is reported, and the complex mechanism has been revealed. It is of great significance for understanding the nature of thermal expansion and guiding the regulation of thermal expansion.
Original language | English |
---|---|
Article number | 4439 |
Journal | Nature Communications |
Volume | 14 |
Issue number | 1 |
DOIs | |
State | Published - Dec 2023 |
Funding
This work was supported by the National Key Research and Development Plan of China (2022YFE0109100), and the National Natural Science Foundation of China (grant nos. 21825102 and 12104038). This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract no. DE-AC02-06CH11357. The authors acknowledge Dr. Chinwei Wang for assisting in collecting the temperature dependence of neutron powder diffraction data using the Wombat high-intensity diffractometer of the Australian Nuclear Science and Technology Organisation (ANSTO).