Backbone NxH compounds at high pressures
Abstract
Optical and synchrotron x-ray diffraction diamond anvil cell experiments have been combined with first-principles theoretical structure predictions to investigate mixtures of N2 and H2 up to 55 GPa. Our experiments show the formation of structurally complex van der Waals compounds [see also D. K. Spaulding et al., Nat. Commun. 5, 5739 (2014)] above 10 GPa. However, we found that these NxH (0.5 < x < 1.5) compounds transform abruptly to new oligomeric materials through barochemistry above 47 GPa and photochemistry at pressures as low as 10 GPa. These oligomeric compounds can be recovered to ambient pressure at T < 130 K, whereas at room temperature, they can be metastable on pressure release down to 3.5 GPa. Extensive theoretical calculations show that such oligomeric materials become thermodynamically more stable in comparison to mixtures of N2, H2, and NH3 above approximately 40 GPa. Our results suggest new pathways for synthesis of environmentally benign high energy-density materials. These materials could also exist as alternative planetary ices.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 05, 2015
- Source ID
- 10.1063/1.4922051
Entities
People
- Adam Berlie
- Alexander Goncharov
- Artem Oganov
- Chaohao Hu
- Chris J. Pickard
- Elissaios Stavrou
- Fei Yen
- Guangrui Qian
- Maddury Somayazulu
- Mahmood Mahmood
- Nicholas Holtgrewe
- Sergey Lobanov
- Vitali Prakapenka
- Zuzana Konopkova
Organizations
- Army Research Office
- Carnegie Institution for Science
- DESY
- Defense Advanced Research Projects Agency
- Guilin University of Electronic Technology
- Helmholtz Association of German Research Centres
- Howard University
- Institute of Solid State Physics
- Ministry of Education and Science of the Russian Federation
- Moscow Institute of Physics and Technology
- National Natural Science Foundation of China
- National Science Foundation
- Natural Science Foundation of Guangxi Province
- Seventh Framework Programme
- Skolkovo Institute of Science and Technology
- State University of New York
- United States Department of Energy
- University College London
- University of Chicago
- University of Science and Technology of China
- V.S. Sobolev Institute of Geology and Mineralogy