High-energy-density pentazolate salts: CaN 10 and BaN 10
- PDF / 1,328,504 Bytes
- 6 Pages / 595.28 x 793.7 pts Page_size
- 43 Downloads / 187 Views
. Article .
January 2021 Vol. 64 No. 1: 218211 https://doi.org/10.1007/s11433-020-1595-2
High-energy-density pentazolate salts: CaN10 and BaN10 JiaNan Yuan, Kang Xia, JueFei Wu, and Jian Sun* National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China Received March 31, 2020; accepted June 17, 2020; published online September 8, 2020
The search for high energy density materials (HEDMs) in polymeric nitrogen compounds has gained considerable attention. Previous theoretical predictions and experiments have revealed that metal ions can be used to stabilize the pentazolate (N−5 ) anion. In this work, by employing a machine learning-accelerated crystal structure searching method and first-principles calculations, we found that the new pentazolate salts, CaN10 and BaN10 , are energetically favorable at high pressures. Phonon dispersion calculations reveal that they are quenchable at ambient pressure. Ab initio molecular dynamics simulations verify their dynamic stability at finite temperature. Bader charge and electron localization function illustrates that alkaline earth atoms serve as electron donors, contributing to the stability of N5 rings. Bonding calculations reveal covalent bonds between nitrogen atoms and weak interactions between N5 rings. Similar to other pentazolate salts, these polymeric nitrides have high energy densities of approximately 2.35 kJ/g for CaN10 and 1.32 kJ/g for BaN10 . The predictions of CaN10 and BaN10 structures indicate that these salts are potential candidates for green nitrogen-rich HEDMs. high energy density material, polymeric nitrogen, pentazolate salts PACS number(s): Citation:
61.50.Ks, 71.15.-m, 71.20.-b
J. N. Yuan, K. Xia, J. F. Wu, and J. Sun, High-energy-density pentazolate salts: CaN10 and BaN10 , Sci. China-Phys. Mech. Astron. 64, 218211 (2021), https://doi.org/10.1007/s11433-020-1595-2
1 Introduction Polymeric nitrogen is a potential candidate as a green high energy density material (HEDM) because it releases a large amount of energy during its decomposition. Polymeric nitrogen contains single and double nitrogen bonds. These single and double bonds have relatively low bond energies (approximately 160 and 418 kJ/mol, respectively) compared with triple bonds (954 kJ/mol) [1]. Thus, single- or double-bonded polymeric nitrogen can release a large amount of energy upon dissociation into triple-bonded nitrogen dimers. Such single and double nitrogen bonds can be formed under extreme conditions such as high temperatures and pressures [2-6]. *Corresponding author (email: [email protected])
Both theoretical and experimental efforts have been made to search for such pure polymeric nitrogen structures with high energy density [2, 7-18]. For instance, Mailhiot et al. [2, 4] successfully synthesized cubic gauche nitrogen (cg-N) containing only single bonds. The energy density of cg-N is approximately five times higher than that of the most powerful energetic materia
Data Loading...
