On measuring the structure stability for small silver clusters to use them in plasmonics

One of the new applications of silver nanoparticles is their use in plasmonic applications determined by the strong interaction of the electromagnetic wave and free electrons in nanostructures. Silver particles of a size smaller than the visible light wavelength can strongly absorb light due to the surface plasmonic resonance caused by the collective oscillation of the conduction electrons. The frequency and intensity of the plasmonic resonance depends on the distribution of the nanostructure polarized charge, which is determined by the shape and structure of the nanoparticle. But the rapid oxidation/sulfidation due to the ambient atmosphere dramatically reduces all the advantages of silver and causes difficulties from the view point of practical applications. Possible solution to this problem could be the formation of very pure particles of a perfect crystal structure, which should be more resistant to the abovementioned phenomena. We believe that unaccounted possibility of increasing the plasmon efficiency can be the usage of silver nanoparticles with a size equal to the magic numbers of various structures. To test this hypothesis, computer simulation was performed to determine the stability of the structure of silver clusters with a size of up to 2.0 nm. It shows that the use of small silver clusters in plasmonic applications strongly requires considering the problem of the thermal stability of their cluster structure with consideration of various kinds of "magic" numbers.