Phase transformations in Au-Fe particles and thin films: Size effects at the micro- and nano-scales

Dor Amram, Oleg Kovalenko, Leonid Klinger, Eugen Rabkin

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Thin Au-Fe bilayers (3-30 nm in total thickness) were deposited on sapphire substrates. Annealing in a temperature range of 600-1100°C resulted in solid-state dewetting and the subsequent formation of micro- and nano-particles. Electron microscopy, atomic force microscopy and in-situ X-ray diffraction were employed to systematically study two phase transformations in the Au-Fe system: (1) precipitation of α-Fe from supersaturated Au-Fe solidsolution particles; (2) α→γ transformation in Fe and Au-Fe thin films and particles. In both cases the transformations proceeded differently than in the bulk already for sub-micron (100 nm - 1 μm) particles. A "reverse size effect" was observed in thin Fe films. These results were explained by the low defect concentration in the particles, nucleation difficulties, slow diffusivity on facets, and Au segregation. The main conclusion is that phase transformations in the particles and in the bulk proceed differently not only for nano-sized particles as was customarily believed, but for particles of sub-micrometer size as well.

Original languageEnglish
Title of host publicationPTM 2015 - Proceedings of the International Conference on Solid-Solid Phase Transformations in Inorganic Materials 2015
EditorsLong-Qing Chen, Matthias Militzer, Gianluigi Botton, James Howe, Chadwick Sinclair, Hatem Zurob
Pages147-154
Number of pages8
ISBN (Electronic)9780692437360
StatePublished - 2015
EventInternational Conference on Solid-Solid Phase Transformations in Inorganic Materials 2015, PTM 2015 - Whistler, Canada
Duration: 28 Jun 20153 Jul 2015

Publication series

NamePTM 2015 - Proceedings of the International Conference on Solid-Solid Phase Transformations in Inorganic Materials 2015

Conference

ConferenceInternational Conference on Solid-Solid Phase Transformations in Inorganic Materials 2015, PTM 2015
Country/TerritoryCanada
CityWhistler
Period28/06/153/07/15

Keywords

  • Au-Fe
  • Particles
  • Phase transformations
  • Size effect
  • Thin films

All Science Journal Classification (ASJC) codes

  • General Chemical Engineering
  • Metals and Alloys
  • Materials Chemistry
  • Inorganic Chemistry

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