Nature Communications (Mar 2024)

Stabilization of N6 and N8 anionic units and 2D polynitrogen layers in high-pressure scandium polynitrides

  • Andrey Aslandukov,
  • Alena Aslandukova,
  • Dominique Laniel,
  • Saiana Khandarkhaeva,
  • Yuqing Yin,
  • Fariia I. Akbar,
  • Stella Chariton,
  • Vitali Prakapenka,
  • Eleanor Lawrence Bright,
  • Carlotta Giacobbe,
  • Jonathan Wright,
  • Davide Comboni,
  • Michael Hanfland,
  • Natalia Dubrovinskaia,
  • Leonid Dubrovinsky

DOI
https://doi.org/10.1038/s41467-024-46313-9
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 9

Abstract

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Abstract Nitrogen catenation under high pressure leads to the formation of polynitrogen compounds with potentially unique properties. The exploration of the entire spectrum of poly- and oligo-nitrogen moieties is still in its earliest stages. Here, we report on four novel scandium nitrides, Sc2N6, Sc2N8, ScN5, and Sc4N3, synthesized by direct reaction between yttrium and nitrogen at 78-125 GPa and 2500 K in laser-heated diamond anvil cells. High-pressure synchrotron single-crystal X-ray diffraction reveals that in the crystal structures of the nitrogen-rich Sc2N6, Sc2N8, and ScN5 phases nitrogen is catenated forming previously unknown N6 6 − and N8 6 − units and $${\!\,}_{\infty }{\!\,}^{2}({{{{{\rm{N}}}}}}_{5}^{3-})$$ ∞ 2 ( N 5 3 − ) anionic corrugated 2D-polynitrogen layers consisting of fused N12 rings. Density functional theory calculations, confirming the dynamical stability of the synthesized compounds, show that Sc2N6 and Sc2N8 possess an anion-driven metallicity, while ScN5 is an indirect semiconductor. Sc2N6, Sc2N8, and ScN5 solids are promising high-energy-density materials with calculated volumetric energy density, detonation velocity, and detonation pressure higher than those of TNT.