The activation energies for several single atom and vacancy diffusion processes on Cu nanowires with an axial orientation of <100> were calculated by using the nudged elastic band technique, based upon the interaction potential obtained from the embedded atom method. It was shown that the dimer-initiated local strain and its relief at the transition state had a significant effect upon the characteristics of self-surface diffusion mechanisms on nanowires. Contrary to the case for cylindrical multi-shell-type Cu nanowires, the vacancy formation energy for rectangular nanowires was maximum in the core region and was nearly zero at the corner of the nanowire. In addition, the activation energy barriers for the vacancy diffusion processes taking place in the core region were found to be higher than those occurring near the corner of the nanowire. The calculations further showed that the vacancy diffusion processes taking place near the corner of the wire were dictated by the lower coordination of the surrounding atoms. From the structural investigation of nanowires, it was also established that multilayer relaxations for rectangular nanowires with smaller cross-sectional area could not be defined.

Energetics and Atomic Relaxations of Cu Nanowires - the Effect of Local Strain and Cross-Sectional Area. B.Onat, M.Konuk, S.Durukanoğlu, G.Dereli: Nanotechnology, 2009, 20[7], 075707 (9pp)