Agrawal B K, Agrawal S, Singh Sanjai
Physics Department, Allahabad University, Allahabad-211002, India.
J Nanosci Nanotechnol. 2005 Apr;5(4):635-40. doi: 10.1166/jnn.2005.053.
An ab initio study of the energetics, structural, and electronic properties of thin silver nanowires of Ag(n) with n = 1 to 6 has been made in density functional theory in local density approximation. The present study reveals that all of the wires are stable except the wire with 3 silver atoms per unit cell. The linear chain is comparatively less stable. The binding energies of the most stable wires lie in the range 2.60-3.18 eV/atom with maximum values for the 5-Ag pentagonal and the two 6-Ag (hexagonal and pyramidal) nanowires. The nearest neighbor Ag-Ag separations in all of the most stable wires up to n=6 is quite the same and is equal to 2.634 +/- 0.03 A. For the most stable 6-Ag pyramidal wire, the bond length increases to 2.75 or 2.81 A. The cross-sectional dimension of these wires are around 5.0 A. All of the studied silver wires are metallic. A majority of the sd mixed states cross the Fermi level. The density of state is maximum for the 5-Ag pentagonal and 6-Ag pyramidal nanowires, and so is the number of channels (5 or 6) crossing the E(F) which would be available for high electrical conduction.
采用局域密度近似下的密度泛函理论，对n = 1至6的Ag(n)细银纳米线的能量学、结构和电子性质进行了从头算研究。本研究表明，除了每个晶胞含3个银原子的纳米线外，所有纳米线都是稳定的。线性链相对不太稳定。最稳定纳米线的结合能在2.60 - 3.18 eV/原子范围内，5 - Ag五角形和两种6 - Ag（六边形和金字塔形）纳米线的结合能最大。直到n = 6的所有最稳定纳米线中，最近邻Ag - Ag间距相当一致，等于2.634±0.03 Å。对于最稳定的6 - Ag金字塔形纳米线，键长增加到2.75或2.81 Å。这些纳米线的横截面尺寸约为5.0 Å。所有研究的银纳米线都是金属性的。大多数sd混合态穿过费米能级。5 - Ag五角形和6 - Ag金字塔形纳米线的态密度最大，穿过费米能级E(F)的通道数（5个或6个）也最多，这些通道可用于高电导率。
