Instability of gold nano-islands in several organic media

The UV-VIS absorption spectroscopy and transmission electron microscopy (TEM) of Au nano-island films, deposited on quartz glass and on amorphous carbon substrate by a sputtering method were applied to study stability or instability of gold nanoparticles in twelve organic liquids with different dielectric constants. The morphology of island films was determined by both TEM and scanning tunneling microscopic observations. The surface plasmon peak characteristic of gold nano-particles showed clear peak shift, peak intensity enhancement and peak width broadening corresponding to the dielectric constants of the liquid. It was also found that the Au island particles on the carbon substrate were destabilized for some kinds of liquids such as benzyl alcohol and dimethylsulfoxide. The balancing of the interactions among Au particle, substrate and liquid materials is crucial to this finding. (C) 1997 Acta Metallurgica Inc.