Nanotwins in Copper Nanowires Controlled by Laser Assisted Electrochemical Deposition

Nanotwins in metallic nanowires can improve mechanical strength and maintain high electrical conductivity. We demonstrated a method of pulse laser assisted electrodeposition, which can generate dense nanotwins with different directions in copper nanowires of uniform length. Transmission electron microcopy characterization shows at lower electrochemical potential of −0.2 Volt, nanotwins tend to align along the longitudinal direction of the nanowires whereas at the high potential −0.8 Volt, nanotwins of {111}/ type that cross the width of the wire are formed. We investigated the two types of nanotwins by comparing the microstructures under different electrochemistry and laser setting. Two different mechanisms are proposed for two kinds of nanotwin — annealing twins and growth twins.© 2012 ASME