Isotope Effects in Diffusion‡‡Work performed under the auspices of the U.S. Atomic Energy Commission.

Peterson, N.L.

doi:10.1016/b978-0-12-522660-8.50008-8

Cited by 30 publications

(3 citation statements)

References 124 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Important quantities to do this are the diffusion isotope effect and the Manning factor. The diffusion isotope effect [1], E, when obtained experimentally, requires a very high level of accuracy in the measurement of the tracer diffusion coefficients. The Manning Factor, S, is formerly called the vacancy-wind factor and is closely related to the Onsager off-diagonal phenomenological coefficient.…”

Section: Introductionmentioning

confidence: 99%

Diffusion: Isotope Effect and Manning Factor in Liquids

Belova¹,

Sarder²,

Paul³

et al. 2022

DDF

View full text Add to dashboard Cite

In this paper, the diffusion isotope effect and the Manning factor are investigated by means of Molecular Dynamics simulations in liquid Cu-Ag alloys. The values for the diffusion isotope effect parameter allow for the estimate of the number of atoms that are moving cooperatively in a basic diffusion event as ‘seen’ by a given (tracer) atom. On average, in the considered alloys and considered temperatures, this is limited to between 5 and 15. This is consistent with results of Molecular Dynamics simulations on the average coordination number calculations. This would suggest that, together with a given atom, a majority of the neighbouring atoms are involved in a basic diffusion event. Results for the Manning factor (MD simulation) for Cu-Ag liquid alloys are seemingly in agreement with the direct exchange mechanism where only two atoms are involved in the elementary diffusion event. This is not in apparent agreement with the isotope effect results. It was shown, however, that any ring mechanism, or, more complex, cage mechanism are, in fact, a combination of several simultaneously happening direct exchanges. Any other possible mechanisms for diffusion in liquids is most likely a combination of direct exchanges as well. It can be seen then that the collective nature of all considered mechanisms is very similar and follows the direct exchange signature properties.

show abstract

Section: Introductionmentioning

confidence: 99%

Diffusion: Isotope Effect and Manning Factor in Liquids

Belova¹,

Sarder²,

Paul³

et al. 2022

DDF

View full text Add to dashboard Cite

show abstract

“…This contrasts with the solid state, where it has been found that measuring the memories or correlations between jumps of tagged atoms can be extremely useful in determining details about the diffusion process. Information about these correlations can be obtained by way of measuring three quantities 1) The Haven Ratio [6] (by comparing the d.c. ionic conductivity and tracer (self) diffusion coefficient in ionic solids), 2) the Manning Factor (formerly called the vacancy-wind factor and which is closely related to the Onsager off-diagonal phenomenological coefficient) which can be determined by comparing the tracer diffusion coefficients of two components, the interdiffusion coefficients and thermodynamic factors in binary (and higher order) alloys [7,8], and 3) the long-time diffusion isotope effect [9] which requires a very high level of accuracy in the measurement of the tracer diffusion coefficients. A very extensive literature has been developed on describing and measurement of all of these effects in solids, see for example [10].…”

Section: Introductionmentioning

confidence: 99%

The Diffusion Isotope Effect and Diffusion Mechanism in Liquid Cu-Ag and Cu-Ni Alloys

Sarder¹,

Paul²,

Belova³

et al. 2021

DDF

View full text Add to dashboard Cite

In this paper, the diffusion isotope effect and diffusion mechanism are investigated by means of molecular dynamics simulations in two liquid alloys, Ni-Ag and Ni-Cu. The values for the diffusion isotope effect parameter allow for the estimate of the number of atoms which are moving cooperatively in a basic diffusion event as experienced by a given atomic species. It is shown that the composition dependence of ND is typically very small. However, the temperature dependence of this parameter is much more pronounced. In addition, it is shown that, on average, in these alloys and temperatures considered, ND is limited to the range: 5<ND<17. This is consistent with results of molecular dynamics simulations on the average coordination number calculations. This would suggest that, together with a given atom, depending on temperature, the neighbouring atoms are all involved in the basic diffusion event.

show abstract

“…Where D is a matrix with elements M kl D and k,l ≠ M. There has been a very long tradition in solid state diffusion research to try to gain access to the tracer correlation factors, if possible, because these factors give rather direct information on the relative degrees of correlation in the random walks of the various atomic species. It is well-known that tracer correlation factors in materials can frequently be inferred directly from isotope effect experiments [19] and, for ionic conductors, from measurements of the Haven Ratio [20]. It is less well-known that tracer correlation factors can also be obtained in concentrated disordered alloys specifically, from ratios of the tracer diffusivities using a diffusion kinetics theory in the random alloy, such as that of Manning [1] or Moleko et al [18].…”

Section: Introductionmentioning

confidence: 99%

Sum-Rule Relations among Phenomenological Coefficients: Application to Segregation and Chemical Diffusion in Multicomponent Alloys and Mixed Ceramic Oxides

Belova¹,

Murch²

2006

DDF

View full text Add to dashboard Cite

In this overview, we discuss the sum-rule relating phenomenological coefficients in randomly mixed systems and consider several applications to collective diffusion problems. These applications include intrinsic diffusion multicomponent alloys, chemical diffusion in strongly ionic mixed cation crystals and demixing of cations in randomly mixed quaternary transition metal oxides. In each case a substantial simplification is possible as a result of the sum-rule.

show abstract

Isotope Effects in Diffusion‡‡Work performed under the auspices of the U.S. Atomic Energy Commission.

Cited by 30 publications

References 124 publications

Diffusion: Isotope Effect and Manning Factor in Liquids

Diffusion: Isotope Effect and Manning Factor in Liquids

The Diffusion Isotope Effect and Diffusion Mechanism in Liquid Cu-Ag and Cu-Ni Alloys

Sum-Rule Relations among Phenomenological Coefficients: Application to Segregation and Chemical Diffusion in Multicomponent Alloys and Mixed Ceramic Oxides

Contact Info

Product

Resources

About