1. Ultra-incompressibility and high energy density of ReN8 with infinite nitrogen chains.
- Author
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Wu, Lailei, Zhou, Pengyuan, Li, Yanguo, Wan, Biao, Sun, Shanhu, Xu, Jinjiang, Sun, Jie, Liao, Bo, and Gou, Huiyang
- Subjects
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TRANSITION metal nitrides , *ENERGY density , *YOUNG'S modulus , *MATHEMATICAL optimization , *ATMOSPHERIC nitrogen - Abstract
Nitrogen-rich transition metal nitrides are of great interests due to the unique physical and chemical properties. Here, we perform a detailed structural investigation of ReN8 in the pressure range of 0–200 GPa via particle swarm optimization algorithm and first-principles calculations. Interestingly, four ReN8 phases are firstly revealed to be stable within 200 GPa, N2 dimers are found to be preferred in T-ReN8 at pressure lower than 15.8 GPa and the infinite N∞ chains become dominated in M-, T'- and M'-ReN8 at higher pressure up to 200 GPa. We find that the Young's moduli of M- and T'-ReN8, about 850 GPa along [0.88 0 0.47] and [0 0 1] direction, are comparable to cubic BN, due to the presence of electronic accumulation in the N∞ chains. Furthermore, M- and T'-ReN8 are found to be of high energy density of ~ 1.9 kJ/g (~ 11.0 kJ/cm3). Ultra-incompressibility of ReN8 in special direction due to the high electronic accumulations in the polynitrogen chains. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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