A Possible Oriented Attachment Growth Mechanism for Silver Nanowire Formation

Electron microscopy studies suggest that silver nanowires prepared by an approach reported earlier by us (Caswell, K. K., Bender, C. M., Murphy, C. J. Nano Lett., 2003, 3, 667-669) form through a coarsening process via an oriented attachment mechanism. Initially, silver nucleation centers were produced by chemical reduction of silver ions in boiling water, with sodium citrate and sodium hydroxide as additives in solution. These nucleation centers, with a twinned crystallographic orientation, ultimately merge into fully grown silver nanowires. This is a completely different mechanism from the seed-mediated growth approach, which has also been used to produce silver nanowires. Companion molecular dynamics performed with the embedded atom method are in agreement with our experimental data.