The Smallest Metallic Nanorods Using Physical Vapor Deposition
  We first present a theory of the smallest diameter and then use the theory to guide the experimental realization of Cu nanorods of ~20 nm in diameter and Au nanorods of ~10 nm in diameter, the smallest well-separated metallic nanorods ever reported using PVD. 
Xiaobin Niu, Stephen P. Stagon, Hanchen Huang, J. Kevin Baldwin and   Amit Misra
cond-mat.mes-hall