Template-confined dewetting of Au and Ag nanoscale films on mica substrate

In this work we report about the template-confined dewetting of Au and Ag nanoscale films on mica substrate toward surface patterning control. In this approach, the Au and Ag surface pattern order, on the mica substrate, is established by the template confined deposition on a micrometric scale, while the dewetting process is induced by thermal process. We expose the results of our studies on the dewetting kinetics both for Au and Ag on mica consisting, in particular, in the identification of three regimes of the process: a regime I in which holes nucleation in the Au and Ag films occurs (characterized by 130 and 72 meV activation energies, respectively); a regime II consisting in the retraction phenomenon of the films limited by the Au or Ag surface diffusion; a regime III corresponding to the merging of the dewetted fronts of holes that come close to each other (and formation of Au and Ag nanoparticles as a consequence). Correspondently, the ordered surface patterns realized for the Au and Ag arrays of nanostructures on a large scale (micrometric) can be changed and controlled for specific applications.