First-principles calculation of the structural and electronic properties of Cu nanowire in different crystallographic directions
MA Liangcai1, ZHANG Jianmin2
(1 College of Physics and Electrical Information Science, Ningxia University, Yinchuan 750021, Ningxia, China;2 School of Physics and Information Technology, Shaanxi Normal University , Xi′an 710119, Shaanxi, China)
Abstract:
Using first-principles calculations based on density-functional theory, the relaxed structures 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 coordinations, the surface atoms relaxed inward and the relaxation amount of the apex atoms was larger, 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 results. The enhanced interactions appear between the surface atoms and their first nearest neighbor 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.
KeyWords:
Cu nanowires; relaxed structures; electronic property; first-principles
