铁二聚体在碳纳米管上的吸附结构和电子性质的理论研究  

Theoretical Study on the Adsorption Structure and Electronic Property of a Iron Dimer on Carbon Nanotube

作　　者：张耀[1] 吕文彩[1,2] 夏临华[1] 

机构地区：[1]青岛大学物理科学学院,青岛266071 [2]吉林大学理论与化学计算国家重点实验室,长春130021

出　　处：《青岛大学学报（自然科学版）》2013年第2期13-18,共6页Journal of Qingdao University(Natural Science Edition)

摘　　要：应用第一性原理计算了双铁原子链吸附在单臂扶手椅纳米管上所形成的二聚体的结构、总能量和电子性质。由于曲率因素,单个铁原子在纳米管内部和外部具有不同的有效配位数,使铁原子在纳米管内外侧吸附在不同的位置。铁原子吸附在单臂纳米管上的稳定性,能带,费米能量,电子及能态密度分布主要依赖于铁原子在纳米管表面的吸附位置。计算结果显示,纳米管外层更有利于铁原子的吸附,并且两个铁原子分别在两个对立的C—C键中心的位置是最稳定的结构。纳米管的内侧,由于纳米管的管状结构,内侧铁原子可以同更多的碳原子保持相对较短的键长,因此碳原子六元环中心成为更稳定的吸附位置。吸附铁二聚体之后,纳米管的导电性明显增强,但是不同的吸附位置会对纳米管产生不同的影响,对纳米管电子性质的改变也会略有差异。First-principles calculations are performed to investigate the structure, total energy and electronic property of a Fe dimer on a single-walled armchair carbon nanotube. The curvature makes nanotube have different coordination numbers for the inner and outer surface atoms, which leads to different positions of adsorptions. The stability, band gap, Fermi energy of the Fe-adsorbed single-wall carbon nanotube systems are found to depend on the location of the Fe atoms absorbed to the carbon nanotube surface. The re sults show that outside adsorbing sites are the most favorable, and the structure with two iron atoms located on the opposite C--C bond-centered positions is the most stable. The inner adsorbing iron atoms on the tube have connections with more carbon atoms in shorter bond length, and the adsorption above the center of the C ring is the most stable. Different absorbing sites have different effects on the nanotubes including the conductivity of the nanotubes.

关 键 词：FE2 C纳米管 态密度 电子性质 

分 类 号：O641.3[理学—物理化学]