碳纳米管与氮化硼纳米管内铜纳米线的形成及其压缩行为

Formation and Compressing Behavior of Copper Nanowires inside Carbon Nanotube and Boron-Nitride Nanotubes

采用分子动力学方法分别对碳纳米管(CNT)与氮化硼纳米管(BNNT)内铜纳米线(CuNW)的形成及其复合结构(CuNW@CNT;CuNW@BNNT)的压缩行为进行了研究。通过对管内充以铜原子BN(5,5)与C(5,5)纳米管的优化,在纳米管轴线上均能生成一维CuNW。其径向分布函数表明:在C(5,5)内生成的CuNW具有更好一维均匀分布性,结晶性相对较佳。而BN(5,5)内的CuNW具有相对较大原子分布密度,可有效地提高一维纳米线导电性。通过对其轴向压缩及其能量分析,可以发现CuNW@C(5,5)复合结构的屈曲应变及能量损失明显大于CuNW@BN(5,5),表明CuNW@C(5,5)具有更强抗压能力,但屈曲发生时对内部CuNW结构保护效应却劣于CuNW@BN(5,5)。

The formation of copper nanowires inside a carbon nanotube （CuNW@CNT） and boron-nitride nanotube （CuNW@BNNT） and the compressing behavior of the resulting composite structure were studied using molecular dynamics. After optimizing C（5,5） and BN（5,5） nanotubes filled with copper atoms, coaxial CuNW with an axial monatomic chain is formed inside the C（5,5） and BN（5,5）. Analysis of the radial distribution function on the CuNWs shows that the CuNW inside CNT has better one-dimensional uniform distribution, whose crystallinity is better. And the CuNW inside BNNT has larger atomic distribution density, which can effectively enhance electrical conductivity for one-dimensional nanowire. Comparison of the axial compressing behavior of CuNW@C（5,5）, CuNW@BN（5,5）, C（5,5） and BN（5,5） reveals that the critical buckling strains and the total potential energy loss of CuNW@C（5,5） composite structure are bigger than that of CuNW@BN（5,5）. The results indicate that the compressive resistance of CuNW@C（5,5） is stronger, but the protective effect on CuNWs at buckling is inferior to that of CuNW@BN（5,5）.