Predicted Pressure-Induced High-Energy-Density Iron Pentazolate Salts
Chuli Sun2, Wei Guo1,2,3*, and Yugui Yao1,2,3
1Frontiers Science Center for High Energy Material (MOE), Beijing Institute of Technology, Beijing 100081, China 2Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, China 3State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
Abstract：Metal-pentazolate compounds as candidates for novel high-energy-density materials have attracted extensive attention in recent years. However, dehydrated pentazolate salts of transition metal iron are rarely reported. We predict two new iron pentazolate salts $Fdd2$-FeN$_{10}$ and $P\bar{1}$(No.1)-FeN$_{10}$ using a constrained crystal search method based on first-principles calculations. We propose that the stable $Fdd2$-FeN$_{10}$ crystal may be synthesized from FeN and N$_{2}$ above 20 GPa, and its formation enthalpy is lower than the reported iron pentazolate salt (marked as $P\bar{1}$(No.2)-FeN$_{10}$). Crystal $P\bar{1}$(No.1)-FeN$_{10}$ is composed of iron bispentazole molecules. Formation enthalpy, phonon spectrum and ab initio molecular dynamics calculations are performed to show their thermodynamic, mechanical and dynamic properties. Moreover, the high energy density (3.709 kJ/g, 6.349 kJ/g) and good explosive performance indicate their potential applications as high-energy-density materials.
2022, Vol. 39 
