Backbone N{sub x}H compounds at high pressures
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 350 Shushanghu Road, Hefei, Anhui 230031 (China)
- Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, Washington, D.C. 20015 (United States)
- Department of Geosciences, State University of New York, Stony Brook, New York 11794-2100 (United States)
- Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004 (China)
- Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, Moscow 143026 (Russian Federation)
- University College London, Gower St., London WC1E 6BT (United Kingdom)
Optical and synchrotron x-ray diffraction diamond anvil cell experiments have been combined with first-principles theoretical structure predictions to investigate mixtures of N{sub 2} and H{sub 2} 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 N{sub x}H (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 N{sub 2}, H{sub 2}, and NH{sub 3} 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.
- OSTI ID:
- 22415938
- Journal Information:
- Journal of Chemical Physics, Vol. 142, Issue 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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