Al与α-Fe_2O_3纳米界面铝热反应的从头计算分子动力学研究

Thermite reaction of Al and α-Fe_2O_3 at the nanometer interface: ab initio molecular dynamics study

在正则系综统下,温度为2000 K时,利用基于密度泛函理论的第一性原理分子动力学计算方法对Al与赤铁矿α-Fe2O3的铝热反应进行了研究.模拟得出Fe—O键的数量随着时间的增加而减小,Al—O键和Fe—Fe键的数量随时间的增加而增大;同时Fe离子总的电荷量随时间的增加而减小,而Al离子总的电荷量随时间的增加而增大.模拟结果表明,在Al/Fe2O3铝热反应中发生了氧化还原反应,Al被氧化,Fe离子被还原;在界面处生成Al—O键,Fe—O键发生断裂;氧化还原反应完成需约3 ps.

Based on the density function theory, thermite reaction between Al and α-Fe2O3 at temperature 2000 K in canonical ensemble is investigated by ab initio molecular dynamics. In the simulation, with the increasing of the time, the number of the Fe—O bond decreases, while the numbers of Al—O bonds and Fe—Fe bonds increase. At the same time, the total charge quantity of Fe ions decreases and the total charge quantity of Al ions increases as time increases. In the Al/Fe2O3 thermite reaction, the redox reaction is observed, Al atoms are oxidized and the Fe ions are reduced. And then the rupture of Fe—O bonds and the formation of Al—O bonds happen at the interface. Whole redox reaction is completed in about 3 ps.