Backbone NxH Compounds at High Pressures

TL;DR

This study combines experimental and theoretical methods to discover new NxH compounds formed under high pressure, revealing potential for novel materials and planetary ice analogs.

Contribution

It introduces the formation of oligomeric NxH compounds at high pressures through mechano- and photochemistry, with implications for material synthesis and planetary science.

Findings

NxH compounds form above 47 GPa via mechano- and photochemistry

These compounds are recoverable to ambient pressure at low temperature

Metastable NxH compounds exist down to 3.5 GPa at room temperature

Abstract

Optical and synchrotron x-ray diffraction diamond anvil cell experiments have been combined with first principles theoretical structure predictions to investigate mixed N2 and H2 up to 55 GPa. We found the formation of oligomeric NxH (x>1) compounds using mechano- and photochemistry at pressures above 47 and 10 GPa, respectively, and room temperature. These compounds can be recovered to ambient pressure at T<130 K, whereas at room temperature, they can be metastable down to 3.5 GPa. Our results suggest new pathways for synthesis of environmentally benign high energy-density materials and alternative planetary ice.