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arXiv · 2501.13292

Observation of molecular and polymeric nitrogen stuffed NaCl ionic layers

Ping Ning·Yifan Tian·Guangtao Liu·Hongbo Wang·Qingyang Hu·Hanyu Liu·Mi Zhou·Yanming Ma
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Abstract

Sodium chloride (NaCl), a ubiquitous and chemically stable compound, has been considered inert under ambient conditions. Its typical B1 structure is highly isotropic without preferential direction, favoring the growth of a three-dimensional network of strong Na-Cl ionic bonds. Here, we employ first-principles structural searching and synchrotron X-ray diffraction to unravel an unexpected chemical reaction between NaCl and N2 to produce a hybrid salt-NaCl(N2)2, where N2 molecules break the isotropic NaCl structure into two-dimensional layers upon synthesis at 50 GPa. In contrast to the insulating properties of pristine NaCl, the electronic bandgap of the N2-stuffed NaCl narrowed to 1.8 eV, becoming an indirect bandgap semiconductor. Further compression to 130 GPa induced the polymerization of N atoms into zigzag N-chains. Our findings not only demonstrate the possibility of unusual N-chemistry under extreme conditions, but also suggest a feasible approach for the design of layered NaCl frameworks to modulate the polymerization of nitrogen.

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Ping Ning, Yifan Tian, Guangtao Liu, Hongbo Wang, Qingyang Hu, Hanyu Liu, Mi Zhou, Yanming Ma. 2025-01-23. Observation of molecular and polymeric nitrogen stuffed NaCl ionic layers. https://arxiv.org/abs/2501.13292

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