Formation of CuxAu1-x phases by cold homogenization of Au/Cu nanocrystalline thin films

Alona Tynkova, Gabor L. Katona, G. Langer, Sergey I. Sidorenko, Svetlana M. Voloshko, D. Beke

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

It is shown, by using depth profiling with a secondary neutral mass spectrometer and structure investigations by XRD and TEM, that at low temperatures, at which the bulk diffusion is frozen, a complete homogenization can take place in the Cu/Au thin film system, which leads to formation of intermetallic phases. Different compounds can be formed depending on the initial thickness ratio. The process starts with grain boundary interdiffusion, which is followed by a formation of reaction layers at the grain boundaries that leads to the motion of the newly formed interfaces perpendicular to the grain boundary plane. Finally, the homogenization finishes when all the pure components have been consumed. The process is asymmetric: It is faster in the Au layer. In Au(25nm)/Cu(50nm) samples the final state is the ordered AuCu3 phase. Decrease of the film thicknesses, as expected, results in the acceleration of the process. It is also illustrated that changing the thickness ratio either a mixture of Cu-rich AuCu and AuCu3 phases (in Au(25nm)/Cu(25nm) sample), or a mixture of disordered Cu- as well as Au-rich solid solutions (in Au(25nm)/Cu(12nm) sample) can be produced. By using a simple model the interface velocity in both the Cu and Au layers were estimated from the linear increase of the average composition and its value is about two orders of magnitude larger in Au (ca. 10-11 m/s) than in Cu (ca. 10-13 m/s).

Original languageEnglish
Pages (from-to)1491-1500
Number of pages10
JournalBeilstein Journal of Nanotechnology
Volume5
Issue number1
DOIs
Publication statusPublished - 2014

Fingerprint

homogenizing
Grain boundaries
thickness ratio
grain boundaries
Thin films
thin films
Interdiffusion (solids)
Depth profiling
Mass spectrometers
mass spectrometers
Intermetallics
intermetallics
Film thickness
Solid solutions
film thickness
solid solutions
Transmission electron microscopy
transmission electron microscopy
Chemical analysis
Temperature

Keywords

  • Cu/Au
  • Grain boundary diffusion
  • Nanofilms of intermetallic compounds
  • Secondary neutral mass spectrometry (SNMS)
  • Solid state reaction

ASJC Scopus subject areas

  • Materials Science(all)
  • Electrical and Electronic Engineering
  • Physics and Astronomy(all)

Cite this

Formation of CuxAu1-x phases by cold homogenization of Au/Cu nanocrystalline thin films. / Tynkova, Alona; Katona, Gabor L.; Langer, G.; Sidorenko, Sergey I.; Voloshko, Svetlana M.; Beke, D.

In: Beilstein Journal of Nanotechnology, Vol. 5, No. 1, 2014, p. 1491-1500.

Research output: Contribution to journalArticle

Tynkova, Alona ; Katona, Gabor L. ; Langer, G. ; Sidorenko, Sergey I. ; Voloshko, Svetlana M. ; Beke, D. / Formation of CuxAu1-x phases by cold homogenization of Au/Cu nanocrystalline thin films. In: Beilstein Journal of Nanotechnology. 2014 ; Vol. 5, No. 1. pp. 1491-1500.
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