Spatial and temporal correlation in tracer diffusion

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The tracer diffusion in intermetallics is the result of highly correlated jump sequences. The spatial correlation between subsequent jumps leads to an essential reduction of diffusivity as expressed by the correlation factor. The temporal correlation of the jump series results in a similar reduction of the effective jump frequencies as measured by quasielastic scattering methods: quasielastic Mössbauer spectroscopy, QMS, or quasielastic neutron spectroscopy, QNS. The proper treatment and comparison of these correlation effect is one of the main challenges of the microscopic theory. The Continuous Time Random Walk method, CTRW, is proposed in this paper as a natural tool to describe both the spatial and temporal correlation effects The encounter model is introduced in the frame of CTRW as an approximate expression for the waiting time distribution. A further simplification is achieved by assuming that reverted jumps dominates the correlation effects. It is shown that under these assumptions a master equation can be established. The effective jump frequencies includes most correlation effects. The general formalism is illustrated for the case of sublattice vacancy mechanism in an Fe3Si type intermetallic compound.

Original languageEnglish
Pages (from-to)327-332
Number of pages6
JournalDefect and Diffusion Forum
Volume143-147
Publication statusPublished - 1997

Fingerprint

Intermetallics
tracers
Spectroscopy
Vacancies
Neutrons
Scattering
intermetallics
simplification
random walk
encounters
spectroscopy
sublattices
diffusivity
formalism
neutrons
scattering

Keywords

  • Encounter Model
  • Intermetallic Compounds
  • Random Walk
  • Spatial Correlation
  • Temporal Correlation

ASJC Scopus subject areas

  • Metals and Alloys

Cite this

Spatial and temporal correlation in tracer diffusion. / Szabó, I.

In: Defect and Diffusion Forum, Vol. 143-147, 1997, p. 327-332.

Research output: Contribution to journalArticle

@article{913907e78b824029a182450f4dce1e8b,
title = "Spatial and temporal correlation in tracer diffusion",
abstract = "The tracer diffusion in intermetallics is the result of highly correlated jump sequences. The spatial correlation between subsequent jumps leads to an essential reduction of diffusivity as expressed by the correlation factor. The temporal correlation of the jump series results in a similar reduction of the effective jump frequencies as measured by quasielastic scattering methods: quasielastic M{\"o}ssbauer spectroscopy, QMS, or quasielastic neutron spectroscopy, QNS. The proper treatment and comparison of these correlation effect is one of the main challenges of the microscopic theory. The Continuous Time Random Walk method, CTRW, is proposed in this paper as a natural tool to describe both the spatial and temporal correlation effects The encounter model is introduced in the frame of CTRW as an approximate expression for the waiting time distribution. A further simplification is achieved by assuming that reverted jumps dominates the correlation effects. It is shown that under these assumptions a master equation can be established. The effective jump frequencies includes most correlation effects. The general formalism is illustrated for the case of sublattice vacancy mechanism in an Fe3Si type intermetallic compound.",
keywords = "Encounter Model, Intermetallic Compounds, Random Walk, Spatial Correlation, Temporal Correlation",
author = "I. Szab{\'o}",
year = "1997",
language = "English",
volume = "143-147",
pages = "327--332",
journal = "Defect and Diffusion Forum",
issn = "1012-0386",
publisher = "Trans Tech Publications",

}

TY - JOUR

T1 - Spatial and temporal correlation in tracer diffusion

AU - Szabó, I.

PY - 1997

Y1 - 1997

N2 - The tracer diffusion in intermetallics is the result of highly correlated jump sequences. The spatial correlation between subsequent jumps leads to an essential reduction of diffusivity as expressed by the correlation factor. The temporal correlation of the jump series results in a similar reduction of the effective jump frequencies as measured by quasielastic scattering methods: quasielastic Mössbauer spectroscopy, QMS, or quasielastic neutron spectroscopy, QNS. The proper treatment and comparison of these correlation effect is one of the main challenges of the microscopic theory. The Continuous Time Random Walk method, CTRW, is proposed in this paper as a natural tool to describe both the spatial and temporal correlation effects The encounter model is introduced in the frame of CTRW as an approximate expression for the waiting time distribution. A further simplification is achieved by assuming that reverted jumps dominates the correlation effects. It is shown that under these assumptions a master equation can be established. The effective jump frequencies includes most correlation effects. The general formalism is illustrated for the case of sublattice vacancy mechanism in an Fe3Si type intermetallic compound.

AB - The tracer diffusion in intermetallics is the result of highly correlated jump sequences. The spatial correlation between subsequent jumps leads to an essential reduction of diffusivity as expressed by the correlation factor. The temporal correlation of the jump series results in a similar reduction of the effective jump frequencies as measured by quasielastic scattering methods: quasielastic Mössbauer spectroscopy, QMS, or quasielastic neutron spectroscopy, QNS. The proper treatment and comparison of these correlation effect is one of the main challenges of the microscopic theory. The Continuous Time Random Walk method, CTRW, is proposed in this paper as a natural tool to describe both the spatial and temporal correlation effects The encounter model is introduced in the frame of CTRW as an approximate expression for the waiting time distribution. A further simplification is achieved by assuming that reverted jumps dominates the correlation effects. It is shown that under these assumptions a master equation can be established. The effective jump frequencies includes most correlation effects. The general formalism is illustrated for the case of sublattice vacancy mechanism in an Fe3Si type intermetallic compound.

KW - Encounter Model

KW - Intermetallic Compounds

KW - Random Walk

KW - Spatial Correlation

KW - Temporal Correlation

UR - http://www.scopus.com/inward/record.url?scp=3042920209&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=3042920209&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:3042920209

VL - 143-147

SP - 327

EP - 332

JO - Defect and Diffusion Forum

JF - Defect and Diffusion Forum

SN - 1012-0386

ER -