Nonlinear stress effects in diffusion

D. Beke, Z. Erdélyi, G. L. Katona

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

According to classical Nernst-Einstein equation the diffusive flux is proportional to the driving force. However, this linear law is not valid if the driving force is very large. Attempts in the literature for the derivation of an "improved relation" till now were mostly restricted to the cases when the diffusion coefficient was independent of the composition. On the other hand, even if there are no externaldriving forces (other than related to the chemical driving force) present, deviations from the Fick I law are expected (transition from parabolic to linear growth-behaviour) on nanoscale for composition dependent diffusion coefficients. General description for the case when the driving forces and the diffusion asymmetry are large, is treated. The special case of large pressure gradients is discussed in detail and their effects on the deviation form the parabolic growth law on nanoscale will be analyzed. Effect of a pressure gradient on the crossover thickness between parabolic and linear regimes and on the interface transfer coefficient, K, is also treated.

Original languageEnglish
Pages (from-to)117-122
Number of pages6
JournalDefect and Diffusion Forum
Volume264
DOIs
Publication statusPublished - 2007

Fingerprint

Pressure gradient
pressure gradients
Chemical analysis
diffusion coefficient
deviation
Fluxes
Einstein equations
crossovers
derivation
asymmetry
coefficients

Keywords

  • Diffusion
  • Large driving forces
  • Nanoscale
  • Stress effects

ASJC Scopus subject areas

  • Metals and Alloys

Cite this

Nonlinear stress effects in diffusion. / Beke, D.; Erdélyi, Z.; Katona, G. L.

In: Defect and Diffusion Forum, Vol. 264, 2007, p. 117-122.

Research output: Contribution to journalArticle

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