铁纳米线-氮化硼纳米管复合结构的形成及其压缩性质的模拟研究

Simulation Research on Formation and Compression Properties of Iron Nanowire and Boron-Nitride Nanotube Composite Stuctures

通过分子动力学理论计算方法对铁纳米线(FeNW)在氮化硼纳米管(BNNT)内的形成及其复合结构(FeNW@BNNT)的压缩性质进行了模拟研究。通过对充以铁原子的BN(5,5)和BN(8,8)纳米管的进行结构优化可以发现,在BN(5,5)纳米管轴线上能生成稳定的一维FeNW,而BN(8,8)纳米管内形成呈螺旋状的三束绞缠的FeNW。其径向分布函数表明在BN(5,5)内生成的FeNW具有良好的一维性且原子分布均匀等特征。通过对BN(5,5)与FeNW@BN(5,5)轴向压缩及其能量分析,可以发现它们虽具有相同屈曲应变,但屈曲前FeNW@BN(5,5)的弹性系数稍大于BN(5,5),且FeNW@BN(5,5)抗压屈曲能力也明显较强。

The formation of iron nanowires inside a boron-nitride nanotube （FeNW@BNNT） and the compressionproperties of the resulting composite structure are studied using molecular dynamics theory method. Optimizing BN（5,5） and BN （8,8） nanotubes filled with iron atoms reveals that coaxial FeNW with an axial monatomie chain isformed inside BN （5,5）, whereas three bouquet of intertwined FeNW with a helical shell are formed inside BN（8,8）.Analysis of the radial distribution function on the FeNWs shows that the FeNW inside BN（5,5） has good one-dimensional uniform distribution. By analyzing on the axial compressing behavior and their energies of BN（5,5） andFeNW@BN （5,5）, it is revealed that their critical buckling strains are same, the coefficient of elasticity beforebuckling for FeNW@BN（5,5） is slightly bigger and its buckling resistance is stronger than those for BN（5,5）.