Dai Wei, He Shi, Ding Kewei, Lu Cheng
School of Mathematics and Physics, Jingchu University of Technology, Hubei448000, China.
Faculty of Materials Science and Chemistry, China University of Geosciences (Wuhan), Wuhan430074, China.
ACS Appl Mater Interfaces. 2022 Oct 26. doi: 10.1021/acsami.2c16293.
Solid nitrogen-rich compounds are potential high-energy-density materials (HEDMs). The enormous challenge in this area is to synthesize and stabilize these energetic materials at moderate pressure and better under near-ambient conditions. Here, we perform an extensive theoretical study on hydronitrogens by the reverse design method considering both energies and energy densities. Four hydronitrogens with different stoichiometries, that is, NH, NH, NH, and NH, are found to be stable at pressures of about 80-300 GPa and metastable with pressure releasing to ambient pressure. The energy densities of these hydronitrogens are about 5.6-6.5 kJ/g and 1.3-1.5 times larger than that of trinitrotoluene (TNT). Most importantly, the phase of the NH compound is an excellent high-temperature superconductor with a of 37.7 K at 72 GPa. The present findings enrich new phases of hydronitrogens under high pressure and characterize their structural and energetic properties and superconductivity, which offer crucial insights for further design and synthesis of exceptional materials with high energy density and high-temperature superconductivity.
固态富氮化合物是潜在的高能量密度材料（HEDMs）。该领域面临的巨大挑战是在中等压力下，最好是在近环境条件下合成并稳定这些含能材料。在此，我们通过考虑能量和能量密度的逆向设计方法，对氢氮化物进行了广泛的理论研究。发现四种不同化学计量比的氢氮化物，即NH、NH、NH和NH，在约80 - 300 GPa的压力下是稳定的，在压力释放到环境压力时是亚稳态的。这些氢氮化物的能量密度约为5.6 - 6.5 kJ/g，比三硝基甲苯（TNT）的能量密度大1.3 - 1.5倍。最重要的是，NH化合物的相是一种优异的高温超导体，在72 GPa时的超导转变温度为37.7 K。目前的研究结果丰富了高压下氢氮化物的新相，并表征了它们的结构、能量性质和超导性，这为进一步设计和合成具有高能量密度和高温超导性的特殊材料提供了关键见解。
