聚合氮的超高压制备及性能计算

Preparation and Performance Calculation of Polymeric Nitrogen under Ultra-high Pressure

为了阐明聚合氮的形成、分解及性能,利用金刚石对顶砧研究了氮气的高压相变行为,在高温高压条件下制备了立方偏转聚合氮(cg-N),完成了结构表征及卸压研究,计算了cg-N在不同压力下的能量性能。结果表明,氮气在升压过程经历了5个相态4个相变点,分别是β-N_(2)相、δ-N_(2)相、ε-N_(2)相、ζ-N_(2)相和η-N_(2)相;其中η-N_(2)相为cg-N的前体,在131.6GPa对其进行激光加热得到了cg-N;cg-N卸压过程中发生了1次相变,其分解压力为33.8GPa;cg-N的晶体结构属于I 213点群,0GPa下的理论密度高达3.398g/cm^(3),爆热为9.58kJ/g,爆速为16.43km/s、爆压为176.45GPa。

In order to clarify the formation,decomposition and properties of polymeric nitrogen,the phase transformation behavior of nitrogen under high pressure was studied using diamond anvil,and the cubic gauche polymeric nitrogen(cg-N)was prepared and characterized.The pressure relief study of cg-N was further carried out and the energy properties under different pressures were calculated.The results show that nitrogen has experienced five phase states,which areβ-N_(2) phase,δ-N_(2) phase,ε-N_(2) phase,ζ-N_(2) phase andη-N_(2) phase,and four phase transition points in the process of increasing pressure.Theη-N_(2) phase is precursor of the cg-N,and the cg-N is obtained by laser heating at 131.6GPa.The cg-N undergoes one phase transition in the pressure relief process and its decomposition pressure is 33.8GPa.The crystal structure of the cg-N belongs to I 213 point group.The density,detonation heat,detonation velocity and detonation pressure of the cg-N at 0GPa are 3.398g/cm^(3),9.58kJ/g,16.43km/s and 176.45GPa,respectively.