Trapping and diffusion behaviors of helium at vacancy in iron from first principles

Liu, Yuelin; Shi, Wenpu

doi:10.1007/s11433-013-5100-y

Cited by 10 publications

(5 citation statements)

References 73 publications

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“…[46,47] reported that the lattice swelling was related to the relaxation volume of the defects by their density functional theory (DFT) simulations. For vacancies and vacancy clus ters, the relaxation volume is negative, while for the selfinter stitial atoms (SIAs), it is positive [46,48,49]. For Kr 2+ ion preirradiation to the fluence of 2.6 × 10 15 ions cm −2 with peak dpa of 10, many vacancies or vacancy clusters are pro duced in the samples.…”

Section: Lattice Changes Tested By Gixrdmentioning

confidence: 99%

Helium retention in krypton ion pre-irradiated nanochannel W film

et al. 2017

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Nanochannel tungsten (W) film is a promising candidate as an alternative to bulk W for use in fusion applications. In previous work it has been shown to have good radiation resistance under helium (He) irradiation. To further understand the influence of the irradiationinduced displacement cascade damage on helium retention behaviour in a fusion environment, in this work, nanochannel W film and bulk W were preirradiated by 800 keV Kr 2+ ions to the fluence of 2.6 × 10 15 ions cm −2 and subsequently irradiated by 40 keV He + ions to the fluence of 5 × 10 17 ions cm −2 . The Kr 2+ ion preirradiation greatly increases helium retention in the form of small clusters and retards the formation of large clusters. It can effectively inhibit surface helium blistering under high temperature annealing. Compared with bulk W, no cracks were found in the nanochannel W film postirradiated by He + ions at high fluence. The release of helium from the nanochannel W film is more than one order of magnitude higher than that of bulk W whether they are irradiated by single He + ions or sequentially irradiated by Kr 2+ and He + ions. Moreover, swelling of the bulk W is more serious than that of the nanochannel film. Therefore, nanochannel W film has a higher radiation tolerance performance in the synergistic irradiation.

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Section: Lattice Changes Tested By Gixrdmentioning

confidence: 99%

Helium retention in krypton ion pre-irradiated nanochannel W film

et al. 2017

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“…1 of Ref. [8] or the schematics in Fig. 1), that the growth rate of a helium-vacancy cluster is mainly determined by the mass-flux of helium towards the trap [9], equivalent to the diffusion behavior.…”

Section: Introductionmentioning

confidence: 90%

“…, if γ ν 0 (8) with µ = 1/m * γ the classical mobility, and Risken's expression [29] based on a cosine-type potential in the low friction limit…”

Section: Stochastic Dynamics Modelmentioning

confidence: 99%

A modified formula for non-Arrhenius diffusion of helium in metals

Wen,

Lai,

Liu

et al. 2019

Preprint

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Helium diffusion in metals is the basic requirement of nucleation and growth of bubble, which gives rise to adverse degradation effects on mechanical properties of structural materials in reactors under irradiation. Lattice based Kinetic Monte Carlo approach is widely adopted to study the evolution of helium-vacancy clustering. However, the implementation of Arrhenius law to prediction the event rate of single interstitial helium solute diffusion in metal is not always appropriate due to low-energy barrier. Based on a stochastic model, a modified formula is derived from the Brownian motion upon a cosine-type potential. Using the parameters obtained from molecular dynamics simulation for the diffusivity of single helium solute in BCC W, the prediction of our model is consistent with the results from dynamical simulation and previous model. This work would help to develop a more accurate KMC scheme for the growth of helium-vacancy clusters, as well as other low-energy reactions in materials science.

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“…H bubble formation is believed to be directly associated with the accumulation of H to defects including vacancy, dislocation and grain boundary in metals [1][2][3][4], which has been tentatively reviewed in Lu et al [9]. Vacancies in metals have already been demonstrated to be trapping centers for H by serious of experimental works [1,4,10] and theoretical studies [11][12][13][14][15]. Moreover, a vacancy trapping mechanism for the H bubble formation in metals has been revealed, suggesting vacancies and other vacancy-type defects can provide an isosurface to accommodate H, which leads to the preliminary stage of H bubble nucleation [14,15].…”

Section: Introductionmentioning

confidence: 99%