| Autor: |
Chen H; Department of Mathematics, Howard University, Washington D.C. 20059 United States.; The Earth and Planets Laboratory Carnegie Science, Washington D.C. 20015, United States., Bykov M; Institute of Inorganic and Analytical Chemistry, Goethe University Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany., Batyrev IG; U.S. Army DEVCOM Army Research Laboratory, FCDD-RLA-WA, Aberdeen Proving Ground, Maryland 21005 United States., Brüning L; Institute of Inorganic and Analytical Chemistry, Goethe University Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany., Bykova E; Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt am Main, Germany., Mahmood MF; Department of Mathematics, Howard University, Washington D.C. 20059 United States., Chariton S; Center for Advanced Radiation Sources, University of Chicago, Argonne, Illinois 60439, United States., Prakapenka VB; Center for Advanced Radiation Sources, University of Chicago, Argonne, Illinois 60439, United States., Fedotenko T; Deutsches Elektronene-Synchrotron DESY Notkestr. 85, 22607 Hamburg, Germany., Glazyrin K; Deutsches Elektronene-Synchrotron DESY Notkestr. 85, 22607 Hamburg, Germany., Mezouar M; European Synchrotron Radiation Facility Grenoble Cedex F-38043 France., Garbarino G; European Synchrotron Radiation Facility Grenoble Cedex F-38043 France., Steele A; The Earth and Planets Laboratory Carnegie Science, Washington D.C. 20015, United States., Goncharov AF; The Earth and Planets Laboratory Carnegie Science, Washington D.C. 20015, United States. |
| Abstrakt: |
High-energy-density materials (HEDMs) are crucial in various applications, from energy storage to defense technologies. Transition metal polynitrides are promising candidates for HEDMs. Using single-crystal synchrotron X-ray diffraction, we investigated the crystal structures of niobium nitride, specifically Nb 2 N 3 and NbN 2 , under high-pressure conditions of up to 86 GPa. At higher pressures, niobium polynitrides NbN 4 and NbN 5 were observed to be stable from 100 to 120 GPa, which feature low-order nitrogen bonding. The low-order bonded nitrogen in NbN 4 and NbN 5 forms multiple polynitrogen anions at megabar pressure ranges. In the Nb-N system, we observed an increasing coordination number of metal-nitrogen as pressure increased. These structures were supported by density functional theory (DFT) calculations and Raman spectroscopy. |
