Pressure stabilized polymeric nitrogen in N2F and N10F compounds

Abstract

Polymeric nitrogen possessing ambient quench recoverability is considered to be the most powerful and green high-energy density material, which has triggered extensive interest. Herein, we predicted two hitherto unknown nitrogen-rich nitrogen fluorine compounds with stoichiometries N2F and N10F using structure searching method and first-principles calculations. N2F and N10F are thermodynamically stable relative to ε-N and fluorine at 67–110 and 87–110 GPa, respectively. Both N2F and N10F encompass N6 rings, forming one-dimensional N∞ ribbons by edge-sharing and three-dimensional channel-like open framework by edge-sharing and two N atoms-bridging, respectively. Phonon spectra calculations and molecular dynamics simulations demonstrate the ambient-pressure quench recoverability of the two predicted phases. Interestingly, after the removal of F atoms from open channel in N10F, the polymeric nitrogen framework mC10-N is retained at ambient conditions with the energy density of 11.20 kJ/g, rendering it a remarkable high-energy density material.

Keywords

• Nitrogen fluorine compounds
• Polymeric nitrogen framework
• First-principles calculations
• High pressure
• High-energy density materials