Solvent self-diffusion in dilute b.c.c. solid solutions

“…We adopted the model of Domain and Becquart [9] which is the extended one of the four-frequency model of the body-centered cubic lattice [10] as the vacancy mechanism and the model of Meslin et al [5] as the interstitial dumbbell mechanism. Both models are based on the result estimated by first-principles calculations.…”

Section: Atomic Processesmentioning

confidence: 99%

Effect of carbon on irradiation-induced grain-boundary phosphorus segregation in reactor pressure vessel steels using first-principles-based rate theory model

Ebihara

Yamaguchi

Nishiyama

et al. 2011

Journal of Nuclear Materials

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“…The vacancy concentration is assumed to be at equilibrium in the low-concentration limit and therefore given by an Arrhenius equation with prefactor unity and with the Gibbs [70,71]. Each distinct jump frequency is indicated, with the red numbers indicating the nearest neighbor with respect to the impurity atom.…”

Section: A Self-diffusionmentioning

confidence: 99%

“…The correlation factor f describes how efficiently the vacancy contributes to the movement of iron atoms. It can be calculated with the nine-frequency model of Le Claire [70,71], which yields a constant value f = 0.727 in the case of self-diffusion in bcc.…”

Section: A Self-diffusionmentioning

confidence: 99%

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First-principles analysis of solute diffusion in dilute bcc Fe- X alloys

2017

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The diffusivities of substitutional impurity elements in iron have been computed with ab inito electronic density functional techniques, using exchange-correlation functional PW91. Excess entropies and the attempt frequency for a jump were determined by calculating phonon frequencies in the harmonic approximation. The influence of the degree of spontaneous magnetization on diffusivity is taken into account by means of the Girifalco model. The activation energy for diffusion has been determined by computing the vacancy formation energy, impurity-vacancy binding energies, migration barrier energies, and the effective energy associated with correlation of vacancy-mediated jump. For each type of impurity atom these contributions have been evaluated and analyzed up to and including the fifth nearest-neighbor shell of the impurity atom. It is found that impurities that have a low migration energy tend to have high effective energy associated with vacancy migration correlation, and vice versa, so that the total diffusion activation energies for all impurities are surprisingly close to each other. The strong effect of vacancy migration correlation is found to be associated with the high migration energy for iron self-diffusion, so that movement of vacancies through the iron bulk is in all cases, except cobalt, the limiting factor for impurity diffusion. The diffusivities calculated with the PW91 functional show good agreement with most of the experimental data for a wide range of elements.

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Solvent self-diffusion in dilute b.c.c. solid solutions

Cited by 51 publications

References 11 publications

Ab-initio based modeling of diffusion in dilute bcc Fe–Ni and Fe–Cr alloys and implications for radiation induced segregation

Ab-initio based modeling of diffusion in dilute bcc Fe–Ni and Fe–Cr alloys and implications for radiation induced segregation

Effect of carbon on irradiation-induced grain-boundary phosphorus segregation in reactor pressure vessel steels using first-principles-based rate theory model

First-principles analysis of solute diffusion in dilute bcc Fe- X alloys

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