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arXiv · 1506.08362

Nitrogen oxides under pressure stability, ionization, polymerization, and superconductivity

Dongxu Li·Artem R. Oganov·Xiao Dong·Xiang-Feng Zhou·Qiang Zhu·Guangrui Qian·Huafeng Dong
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Abstract

Nitrogen oxides are textbook class of molecular compounds, with extensive industrial applications. Nitrogen and oxygen are also among the most abundant elements in the universe. We explore the N-O system at 0 K and up to 500 GPa though ab initio evolutionary simulations. Results show that two phase transformations of stable molecular NO2 exist at 7 and 64 GPa, and followed by decomposition of NO2 at 91 GPa. All of the NO+NO3- structures are found to be metastable at T=0 K, so experimentally reported ionic NO+NO3- is either metastable or stabilized by temperature. Upon increasing pressure, N2O5 transforms from P-1 to C2/c structure at 51 GPa. NO becomes thermodynamically stable at 198 GPa. This polymeric phase is superconducting (Tc = 2.0 K) and contains a -N-N- backbone.

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Dongxu Li, Artem R. Oganov, Xiao Dong, Xiang-Feng Zhou, Qiang Zhu, Guangrui Qian, Huafeng Dong. 2015-06-28. Nitrogen oxides under pressure stability, ionization, polymerization, and superconductivity. https://arxiv.org/abs/1506.08362

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