Characteristic length scale of nanorod diameter during growth

This Letter proposes a characteristic length scale on surfaces and demonstrates its impact on nanorod growth. The proposed length scale is the dimension of a surface segment bounded by multiple-layer steps. Lattice kinetic Monte Carlo simulations, taking Cu as the prototype of nanorods, show that the proposed length scale (i) exists as the result of a diffusion barrier of adatoms down multiple-layer steps, (ii) dictates that the diameter of metallic nanorods is on the order of several hundred nanometers, and (iii) sets the upper limit of the facet dimension.