Robust high pressure stability and negative thermal expansion in sodium-rich antiperovskites Na3OBr and Na4OI2
- Univ. of Nevada, Las Vegas, NV (United States); Huanghe Science and Technology College, Henan (China); Carnegie Inst. of Washington, Argonne, IL (United States)
- Huanghe Science and Technology College, Henan (China)
- Carnegie Inst. of Washington, Argonne, IL (United States)
- Univ. of Nevada, Las Vegas, NV (United States)
The structure stability under high pressure and thermal expansion behavior of Na3OBr and Na4OI2, two prototypes of alkali-metal-rich antiperovskites, were investigated by in situ synchrotron X-ray diffraction techniques under high pressure and low temp. Both are soft materials with bulk modulus of 58.6 GPa and 52.0 GPa for Na3OBr and Na4OI2, resp. The cubic Na3OBr structure and tetragonal Na4OI2 with intergrowth K2NiF4 structure are stable under high pressure up to 23 GPa. Although being a characteristic layered structure, Na4OI2 exhibits nearly isotropic compressibility. Neg. thermal expansion was obsd. at low temp. range (20-80 K) in both transition-metal-free antiperovskites for the first time. The robust high pressure structure stability was examined. and confirmed by first-principles calculations. among various possible polymorphisms qualitatively. The results provide in-depth understanding of the neg. thermal expansion and robust crystal structure stability of these antiperovskite systems and their potential applications.
- Research Organization:
- Univ. of Nevada, Las Vegas, NV (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Office of Defense Science (NA-113)
- Grant/Contract Number:
- NA0001982
- OSTI ID:
- 1332788
- Journal Information:
- Journal of Applied Physics, Vol. 119, Issue 2; ISSN 0021-8979
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Antiperovskites with Exceptional Functionalities
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journal | November 2019 |
Electronic structure, thermomechanical and phonon properties of inverse perovskite oxide (Na 3 OCl): An ab initio study
|
journal | December 2019 |
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