Azina group: Nanostructures & Complex Materials (NCM)

 

Scope

The independent multidisciplinary “Nanostructures & Complex Materials” research group, led by Dr. Clio Azina, JPI Fellow 2021, is focusing on the design and development of novel multifunctional materials for energy and health-related applications. We strive to carry out our research in an environmentally conscious manner by:

  • Exploring environmentally friendly processes for the production of nanostructures
  • Contributing to critical material replacement by developing new materials

We stand at the interface between chemistry and physics, and combine different synthesis processes to produce thin films, nanoobjects and bulk materials.

 

Sputtering onto Liquids

Our current research activities include the development of a sustainable process for producing nanoparticles by sputtering onto liquids (SoL). Low volatility liquids such as vegetable oils, ionic liquids and certain polymers, are excellent solvents for forming and dispersing metallic and ceramic nanoparticles.

  Process route Copyright: © Azina

Representation of the SoL steps:

I. preparing the liquid substrate and positioning it in the deposition chamber

II. Sputtering process

III. Colloidal suspension of Ag nanoparticles sputtered onto castor oil. STEM micrographs of the produced Ag nanoparticles (appearing in dark).

 

Antibacterial (nano)composite coatings

We are also interested in describing the mechanisms of formation of nanocomposite coatings produced by co-sputtering. The energetic parameters intervening allow tuning microstructures, phase formation, and compositions, which will affect the properties of the coatings.

 

Metallische Gläser: Ag-Nanokomposite abgeschieden von gläsernen Komposittargets. Substrattemperatur und -biaspotential während der Schichtsynthese beeinflussen die Ag-Verteilung und Mikrostruktur in der Dünnschicht, wodurch wiederum die elektrische Leitfähigkeit der Schichten verändert wird.

[Steinhoff, M.K.; Holzapfel, D.M.; Karimi Aghda, S.; Neuß, D.; Pöllmann, P.J.; Hans, M.; Primetzhofer, D.; Schneider, J.M.; Azina, C. Ag Surface and Bulk Segregations in Sputtered ZrCuAlNi Metallic Glass Thin Films. Materials 2022, 15, 1635, doi:10.3390/ma15051635]

  Ag Thin Films Copyright: © Azina

TiO2:Ag nanocomposite obtained by co-sputtering of Ti and Ag in reactive O2 atmosphere. After annealing to 700 °C, the Ag segregates. In the micrograph, the Ag segregation is covered by a SiO2 layer.

 

Compositionally complex thermal barrier coatings

The aim here is to develop compositionally complex oxide coatings which possess low thermal conductivities. We seek to identify promising complex oxides containing up to 5 metals. We then aim to point out the influence of the size, electron configuration and coordination number of the various metals on the phase formation, thermal properties and thermal stability of the produced oxides.