The search for stable novel polynitrogen clusters has garnered significant attention in the field of energetic materials due to their potential applications as high-energy-density materials.In this study,a chair-like ...The search for stable novel polynitrogen clusters has garnered significant attention in the field of energetic materials due to their potential applications as high-energy-density materials.In this study,a chair-like N_(6)^(6-) ring with N-N single bonds in the AlN_(3) compound is theoretically predicted through first-principles calculations in conjunction with an unbiased structure searching method.The predicted AlN_(3) phase exhibits high kinetic and thermodynamic stability,along with a high energy density of 5.04 kJ/g relative to AlN and N_(2) gas.Additionally,its detonation velocity and pressure are estimated to reach 12.93 km/s and 1009.63 kbar,respectively.These values are greater than those of TNT and HMX,positioning it as a promising candidate for high-energy-density materials in the field of explosive combustion.The analysis of electronic properties and the related chemical bonding patterns indicates that the compounds are stabilized by both Coulomb interactions and covalent bonds.More importantly,the calculated formation of enthalpy indicates that the N_(6)^(6-)anions within AlN_(3) can be synthesized by compressing AlN and N_(2) at a moderate pressure(46 GPa).These findings present a viable approach for synthesizing and stabilizing the all-nitrogen N_(6)^(6-)anions.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No.11974154)the Taishan Scholars Special Funding for Construction Projectsthe Natural Science Foundation of Shandong Province (Grant No.ZR2022MA004)。
文摘The search for stable novel polynitrogen clusters has garnered significant attention in the field of energetic materials due to their potential applications as high-energy-density materials.In this study,a chair-like N_(6)^(6-) ring with N-N single bonds in the AlN_(3) compound is theoretically predicted through first-principles calculations in conjunction with an unbiased structure searching method.The predicted AlN_(3) phase exhibits high kinetic and thermodynamic stability,along with a high energy density of 5.04 kJ/g relative to AlN and N_(2) gas.Additionally,its detonation velocity and pressure are estimated to reach 12.93 km/s and 1009.63 kbar,respectively.These values are greater than those of TNT and HMX,positioning it as a promising candidate for high-energy-density materials in the field of explosive combustion.The analysis of electronic properties and the related chemical bonding patterns indicates that the compounds are stabilized by both Coulomb interactions and covalent bonds.More importantly,the calculated formation of enthalpy indicates that the N_(6)^(6-)anions within AlN_(3) can be synthesized by compressing AlN and N_(2) at a moderate pressure(46 GPa).These findings present a viable approach for synthesizing and stabilizing the all-nitrogen N_(6)^(6-)anions.
