Gold-assisted growth of oxide bases underneath dewetted gold nanoparticles

The self-assembly of oxide bases, from nominally stable oxide substrates, underneath dewetted gold nanoparticles have been replicated in Au-SrTiO ₃ , the same as the recently-reported case in Au-MgAl ₂ O ₄ . Both grown bases have the same morphology and crystallographic characters, and are associated to the formation of strong interfaces. To reveal the underlying growth mechanism, we establish a thermodynamic model, estimating that the decrease in the total surface and interfacial energy of gold-oxide nanostructures cannot be compensate the energy increase for growing bases. Other factors, including the surface energy decrease during gold vaporization, are suggested to be partially responsible for the base growth. Our results suggest new possibilities in controlling the synthesis of gold-oxide nanostructure.