Scanning tunneling microscopy study of the relaxation mechanism of a Au(100) nanostructure

The three-dimensional shape relaxation of gold nanostructures was studied by scanning tunneling microscopy in real time and at ambient conditions. The nanostructures were fabricated on a Au(100) single crystal by a two step-process: electrochemical etching to produced a rough surface, followed by thermal annealing. The nanostructures can be described as mounds having small semicircular facets that shrink in time, peeling away layer by layer as a result of the sudden temperature change and evolving towards thermodynamic equilibrium. A model developed by Uwaha is used to describe the dynamic evolution of the peeling layers, where good agreement was found despite the presence of adsorbates due to ambient exposure.