Lenticular Ga-oxide nanostructures in thin amorphous germanosilicate layers - Size control and dimensional constraints

Jacopo Remondina, Silvia Trabattoni, Adele Sassella, Nikita V. Golubev, Elena S. Ignat'eva, Vladimir N. Sigaev, Maurizio Acciarri, Benedikt Schrode, Roland Resel, Alberto Paleari*, Roberto Lorenzi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Gallium incorporation in silicate glasses gives rise to compounds in which the nucleation and growth of Ga-oxide nanostructures can be designer controlled so as to obtain a number of functional properties for photonic applications. However, despite planar geometry pertains to a large part of modern technology, no information is available yet on the scalability of Ga-oxide segregation mechanisms in oxide thin films. In fact, incorporated Ga-oxide nanostructures have only been obtained in bulk materials. Here we show that deposition of Ga-alkali-germanosilicate thin films by radiofrequency-plasma sputtering gives rise to Ga-oxide nanostructures incorporated in an amorphous matrix. X-ray diffraction, X-ray reflectivity, small-angle X-ray scattering, and atomic force microscopy data unveil the formation of lenticular nanoaggregates, only a few nm thick, even in as-deposited materials as a result of two-dimensional aggregation of spinel-like Ga 2O 3 nanoparticles. Importantly, the aggregate size distribution is controlled not only by the temperature but also by the film thickness when it is reduced from 10 2 nm to only a few nm. The results open the way to the design of oxide-in-oxide thin films with incorporated networks of nanostructures which can act as percolation paths for unconventional electric responses in neuromorphic functional systems.

Original languageEnglish
Article number109667
JournalMaterials and Design
Publication statusPublished - Jun 2021


  • Atomic-force-microscopy
  • Gallium oxide
  • Nanostructured glassceramic materials
  • Oxide thin films
  • Silicates
  • X-ray scattering analysis

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Materials Science(all)


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