Segregation and phase separation in thin films

Research output: Article

3 Citations (Scopus)

Abstract

Surface segregation and phase separation in binary AB systems have been calculated in a slab consisting of atomic planes perpendicular to the free surfaces. For strongly segregating systems, if the average concentration lies in the two phase region of the binary phase diagram, a phase separation from the surfaces develops and two layers of the A-rich phase cover the A-poor central phase in the slab (lamellar structure). Furthermore, there is an enrichment (segregation) of A atoms in the near surface layers of the upper phase. For weakly segregating systems there exists a critical concentration Ch. If T > Th (Th is the temperature on the miscibility gap at Ch), a similar phase separation and segregation has been observed as above. However, for T <Th, two different phases can be in equilibrium in a columnar structure. The concentrations in their central layers, if the slab is thick enough, correspond to the compositions of the miscibility gap at the given temperature. At the same time, there is a strong segregation of A atoms in the A-poor phase, while, due to the stronger separation tendency, the minority B atoms will 'separate' at the surface, leading to a desegregation of A atoms in the A-rich phase.

Original languageEnglish
Pages (from-to)195-204
Number of pages10
JournalNanostructured Materials
Volume10
Issue number2-8
Publication statusPublished - febr. 1998

Fingerprint

Phase separation
Thin films
Atoms
thin films
miscibility gap
slabs
Solubility
Surface segregation
Lamellar structures
atoms
Phase diagrams
minorities
Temperature
surface layers
tendencies
Chemical analysis
phase diagrams
temperature

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Segregation and phase separation in thin films. / Cserháti, C.; Szabó, I.; Beke, D.

In: Nanostructured Materials, Vol. 10, No. 2-8, 02.1998, p. 195-204.

Research output: Article

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