By slowing the rate of atomic addition to singly twinned seeds, we have grown silver nanobeams with lengths of 3-30
![](/images/entities/mgr.gif)
m, widths rangingfrom 17 to 70 nm, and a width to thickness ratio of 1.4. The well-defined dimensions, smooth surface, and crystallinity of nanobeams makethem promising candidates for studying the effects of size on electron transport. With a simple method that allows rapid characterization ofsingle nanobeams, we find that even the thinnest nanobeams largely retain the low resistivity of bulk silver. Nanobeams can support remarkablyhigh current densities of up to 2.6 × 10
8 A cm
-2 before the conduction path is broken by the formation of a nanogap.