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Bending of nanoporous thin films under ion radiation
Publikationstyp
Journal Article
Date Issued
2019-07-11
Sprache
English
Journal
Volume
688
Article Number
137419
Citation
Thin Solid Films 688 (): 137419 (2019)
Publisher DOI
Scopus ID
Publisher
Elsevier
In general, fundamental understanding of radiation resistance of high surface density nanoporous materials and nanoporous coatings is severely lacking. In this contribution ion-induced bending phenomena are studied in free-standing nanoporous Au cantilevers with thickness in the range of 100 to 200 nm. Experiments were performed in a Tescan Lyra dual beam system with Ga+ ion irradiation normal to the sample surface up to a maximum fluence of ~3 × 1019 m−2. Cantilevers bend towards the incident ion beam. It was found that the sensitivity of nanoporous Au samples to radiation-induced bending is substantially higher in comparison to the solid bulk counterparts. The process is described in terms of ion-induced coarsening of the structure top layers, which generates a volume contraction responsible for the bending moment. Therefore it is concluded that radiation-induced coarsening/sintering leads to negative swelling. Radiation-modified effective Young's modulus of the top layers was shown to influence essentially the fluence dependence of bending curvature. Model predictions agree well with our experimental findings showing that inhomogeneous radiation-induced coarsening of nanoporous structure results in bending and that nanoporous materials are less suitable for coatings in nuclear applications under the test conditions.
Subjects
Focussed ion-beam processing
Ion-induced bending
Nanostructure manipulation
Radiation damage
DDC Class
530: Physik
540: Chemie