碳及内嵌金属原子富勒稀分子的压缩力学特性

Mechanical characters of compressed C_n and endohedral M@C_(60) fullerene molecules

采用分子动力学(MD)与量子力学(QM)相结合的方法,模拟了Cn(n=20、60、80、180)富勒稀分子,以及M@C60(M=Na、Fe、Al)内嵌金属原子富勒稀分子的对径压缩过程,获得了各种富勒稀分子的系统能量-变形曲线、载荷-变形曲线、最大承受载荷、失效应变以及压缩刚度等压缩力学性能数据.根据模拟的结果,分析了具有不同幻数n、不同内嵌金属原子的富勒稀分子压缩力学特性的差异.研究表明,碳富勒稀分子具有出色的压缩力学性能;幻数n较大的富勒稀分子的最大承受载荷和压缩刚度较大,但失效应变较小;与未填充碳富勒稀分子相比,内嵌金属原子富勒稀分子具有更好的承载能力.

By use of the molecular dynamics and quantum mechanics combined method (MD/QM method), the mechanical properties of compressed Cn (n = 20, 60, 80, 180) and endohedral M@C60 (M = Na, Al, Fe) fullerene molecules are investigated. According to the calculated results, differences of the mechanical properties of the compressed C20, C60, C80, C180 and M@C60 (M = Na, Al, Fe) are discussed as well. The results show that, (1) compressed fullerene molecules take on outstanding mechanical properties; (2) the bigger the magic number n for an empty fullerene is, the higher its load support capability Fmax and stiffness are, but the lower its invalidation strain li is; (3) all the M@C60 molecules have higher support capability Fmax and invalidation strain li than empty C60 molecule.