摘要
基于密度泛函理论框架下的第一性原理计算方法,系统研究了[100]、[110]和[111]3个低指数晶向不同尺寸Cu纳米线的弛豫结构和电子特性。由于配位数的减少,纳米线表面原子向内收缩且角部区域内的原子弛豫量较大,即存在着"倒棱"现象。纳米线的结合能随着其线径的增加而增加,[110]晶向六边形结构的Cu纳米线最稳定,这与在实验中最容易形成该晶向纳米线的结果一致。纳米线表面原子与其最近邻原子间的相互作用明显增强,因此相对于体相Cu晶体,纳米线的力学性能得以提高。所有Cu纳米线都具有金属性,且其量子电导随着线径的增加而增大。
Using first-principles calculations based on density-functional theory,the relaxed struc-tures and electronic properties have been investigated for Cu nanowires in [100],[110]and [111]crystallographic directions with different cross sections.Due to the reduced atomic coordi-nations,the surface atoms relaxed inward and the relaxation amount of the apex atoms was lar-ger,which result in a round corner phenomenon for Cu nanowires.The binding energy per bond shows significant increase with the size of the nanowire.The [110]crystallographic wire is more stable than the others and easily synthesize in experiment,which agrees with the experimental re-sults.The enhanced interactions appear between the surface atoms and their first nearest neigh-bor atoms,which enhances the mechanical properties of the nanowire compared to bulk.All the nanowires are metallic and the quantum conductance increases with the diameter of nanowire.
出处
《陕西师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2015年第2期28-33,共6页
Journal of Shaanxi Normal University：Natural Science Edition
基金
宁夏自然科学基金资助项目(NZ14013)
关键词
Cu纳米线
弛豫结构
电子性质
第一性原理
Cu nanowires
relaxed structures
electronic property
first-principles
