Nanostructured Ag4O4 thin films produced by ion beam oxidation of silver

We report on the synthesis of nanostructured Ag4O4 by thermal evaporation of silver films followed by oxidation with beams of oxygen ions with different kinetic energy in the 50-300 eV range. This method, which combines simplicity and versatility, allows to control the oxide structural properties, and in particular to obtain Ag4O4 thin films characterized by different nanoscale morphologies and crystalline structure, depending on the pristine silver layer morphology and on the energy of the oxygen ions. Monoclinic and tetragonal Ag4O4 phases, or a mixture of the two, can be obtained. The nanoscale porosity of the material makes it interesting for applications where surface mediated Ag ion release plays a crucial role.

► Nanostructured Ag films are irradiated by oxygen ion beams with kinetic energy in the range 50-300 eV. ► Nanostructured Ag4O4 layers are obtained. ► Morphology and crystalline phase of the oxide depend on ion energy and Ag film morphology. ► Tetragonal and monoclinic Ag4O4 crystalline structures are obtained. ► Oxidation with atomic oxygen leads to the formation of peculiar Ag4O4 lamellar nanostructures.