Manipulating the size distribution of supported gold nanostructures

Gold nanostructures, with a wide size distribution, are confined between a metal foil and the oxide substrate upon which they were formed. When heated the surface energy gradient between the oxide and foil results in a net migration of gold atoms from the nanostructure to the foil. With time, the nanostructures show a size reduction and a narrowed size distribution. The narrowing results from the formation of foil contact points with only the largest nanostructures, a characteristic which leaves small nanostructures intact while consuming larger ones. Also demonstrated is the size reduction of arrayed gold structures to nanoscale dimensions.