Ni原子链填充碳纳米管的能量、电子结构和磁性的第一性原理计算

Energies,electronic structures and magnetic properties of Ni atomic chain encapsulated in carbon nanotubes:a first-principles calculation

在广义梯度近似(GGA)下,利用密度泛函理论(DFT)框架下的第一性原理投影缀加波(PAW)赝势方法,研究了单根Ni原子链填充扶手椅型(n,n)(5≤n≤9)单壁碳纳米管的能量、电子结构和磁性.结果表明(5,5)碳纳米管直径过小排斥Ni原子链的插入,(6,6)碳纳米管是容纳Ni原子链的最小碳纳米管,特别是Ni原子链位于其中心轴线上时的形成能最低.以Ni@(6,6)和Ni@(7,7)系统为例,计算并分析了其自旋极化能带结构,电子总态密度,分波态密度和磁性,发现Ni原子的3d态电子对费米能级处的总态密度起决定作用,直径较大的碳纳米管对内部Ni原子链的磁矩限制较弱.

In the generalized gradient approximation （GGA）, energies, electronic structures and magnetic properties have been investigated for a single Ni atomic chain encapsulated in an armchair single-wall （ n,n ） carbon nanotubes （ 5 ≤ n ≤ 9 ） by using the first-principles projector augmented wave （PAW） potential within the density function theory （DFT） framework. The results show that the （5,5） tube is too narrow to wrap a Ni atomic chain, but the （6,6） tube is the smallest one to wrap a Ni atomic chain, especially at its central axis due to the lowest formation energy. The analyses of the spin-polarized band structures, total density of states （ DOS）, partial density of states （PDOS） and the magnetic moment of Ni@ （6,6） and Ni@ （7,7） systems show that the 3d states of Ni atom play determinant rales in DOS at the Fermi level, and the broader carbon nanotubes restrict slightly the magnetic moment of Ni atomic chain compared with with the narrower ones.