Experimental observation of large ramified Au aggregates on melting glass surfaces

Abstract

We report the formation of large ramified gold aggregates after deposition of Au on melting glass surfaces. The growth mechanism of the aggregates is traced to a two-stage process, the first of which involves nucleation and growth of compact Au clusters. The average diameter of the clusters is around 1.2 \ensuremath{\mu}m, which is approximately independent of the deposition rate. In the subsequent stage, the clusters diffuse randomly on the colloid surface and the diffusion coefficient is in the range between ${10}^{\ensuremath{-}7}$ and ${10}^{\ensuremath{-}8}{\mathrm{cm}}^{2}/\mathrm{s}.$ Finally they aggregate. It is found that the structure of the aggregates strongly depends on the aggregation time.