Diffusion of point defects, nucleation of dislocation loops, and effect of hydrogen in hcp-Zr: Ab initio and classical simulations

Christensen, Mikael; Wolf, W.; Freeman, C. M.; Wimmer, E.; Adamson, Ronald B.; Hallstadius, Lars; Cantonwine, Paul; Mader, E. V.

doi:10.1016/j.jnucmat.2015.02.013

Cited by 68 publications

(25 citation statements)

References 58 publications

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“…The segregation is coincident with dislocation positions, which has been shown for Fe and Cr segregation in the vicinity of Fe-Cr type SPPs at similar distances from the SPPs to those presented here [12,64]. Recent calculations have shown that Fe, Cr and Ni diffusion is anisotropic with a preference in the 0001 direction [65], the diffusion of Zr self interstitials (SIAs) is anisotropic with preferable diffusion in the basal plane and the diffusion of vacancies is only weakly anisotropic [14,66]. As such, the segregation of Fe, Cr and Ni to basal planes in Figure 7 and Figure 8 cannot be a result of their individual diffusion anisotropy but is likely due to the diffusion of SIAs in the basal plane toward SPPs and the resulting back diffusion of alloying elements in the reverse direction.…”

Section: Spp Dissolution and Amorphisationsupporting

confidence: 82%

Nano-scale chemical evolution in a proton-and neutron-irradiated Zr alloy

Harte

Topping

Frankel

et al. 2017

Journal of Nuclear Materials

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A. Harte et al., Nano-scale chemical evolution in a proton-and neutron-irradiated Zr alloy J. Nucl. Mater. Accepted Jan. 2017 Nano-scale chemical evolution in a proton-and neutron-irradiated Zr alloy (Fe,Ni). This is accomplished through ultra-high spatial resolution scanning transmission electron microscopy and the use of energy-dispersive X-ray spectroscopic methods. Fe-depletion is observed from both SPP types after irradiation with both irradiative species, but is heterogeneous in the case of Zr(Fe,Cr) 2 , predominantly from the edge region, and homogeneously in the case of Zr 2 (Fe,Ni). Further, there is evidence of a delay in the dissolution of the Zr 2 (Fe,Ni) SPP with respect to the Zr(Fe,Cr) 2 . As such, SPP dissolution results in matrix supersaturation with solute under both irradiative species and proton irradiation is considered well suited to emulate the effects of neutron irradiation in this context. The mechanisms of solute redistribution processes from SPPs and the consequences for irradiation-induced growth phenomena are discussed.

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Section: Spp Dissolution and Amorphisationsupporting

confidence: 82%

Nano-scale chemical evolution in a proton-and neutron-irradiated Zr alloy

Harte

Topping

Frankel

et al. 2017

Journal of Nuclear Materials

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“…[16][17][18][19] A more detailed description of the fitting procedures ( Figure S2), capabilities and methods related to this module can be found in the study of France-Lanord et al 17 The same module was successfully applied in other studies. [18][19] For each frame obtained from the AIMD simulations, total potential energy, forces along x, y, and z for each atom, and stress along x, y, and z are recorded. However, only atomic forces were used in the current forcefield parameters optimization.…”

Section: Si-2: In-mil-68-nh2 Forcefield Parameterizationmentioning

confidence: 99%

“…[17][18][19] Due to the limited number of parameters to optimize, each one was individually fitted iteratively through mean-square minimization of the forces computed with VASP (from the training set) and LAMMPS. First, we optimized the equilibrium bond distance or angle, followed by optimization of the force constant.…”

Section: Si-3: Pcff+ Fitted Parameters For In-mil-68-nh2mentioning

confidence: 99%

Molecular Level Characterization of the Structure and Interactions in Peptide‐Functionalized Metal–Organic Frameworks

Todorova

Rozanska

Gervais

et al. 2016

Chemistry A European J

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We use DFT, newly parameterized Molecular Dynamics simulations and last generation 15 N DNP surface enhanced solid-state NMR spectroscopy to understand graft-host interactions and effects imposed by the MOF host on peptide conformations in a peptide-functionalized MOF. Focusing on two grafts typified by MIL-68-Proline (-Pro) and MIL-68-Glycine-Proline (-Gly-Pro), we identified the most likely peptide conformations adopted in the functionalized hybrid frameworks. We found that hydrogen bond interactions between the graft and the surface hydroxyl groups of the MOF are key in determining the peptides conformation(s).15 N DNP SENS methodology shows unprecedented signal enhancements when applied to these peptide-functionalized MOFs. The calculated chemical shifts of selected MIL-68-NH-Pro and MIL-68-NH-Gly-Pro conformations are in a good agreement with the experimentally obtained 15 N NMR signals. The study shows that the conformations of peptides when grafted in a MOF host are unlikely to be freely distributed, and conformational selection is directed by strong host-guest interactions.

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“…For all polycrystalline materials, the consequences of intergranular segregation on structural and functional properties are considerable: embrittlement or consolidation, intergranular corrosion and modification of electrical properties [2]. * corresponding author; e-mail: selm2002nor@yahoo.fr Several studies have been carried out on crystal defects of metals having the hexagonal close-packed structure such as Mg, Ti, and Zr [3], particularly on the atomic scale, by ab initio calculations [4][5][6][7][8][9][10] or by molecular dynamics [11,12].…”

Section: Introductionmentioning

confidence: 99%

<i>Ab Initio</i> Study of Tin Segregation in Zirconium at the Σ17(0̅337) Tilt Grain Boundary

2019

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Zircaloy-2 and zircaloy-4 contain alloying elements that improve their mechanical properties and corrosion resistance. However, the segregation of these alloying elements affects considerably these properties. In this work, the steps of constructing a symmetrical tilt grain boundary in hcp structure are described and the segregation energy of Sn in the symmetric tilt grain boundary Σ17[θ = 49.71 • /[2110], (0337)] in Zr is also calculated using the first principles ab initio and the ABINIT calculation code. Among five selected pseudopotentials, the optimization and convergence calculations for the bulk hcp Zr lattice show that the most optimal pseudopotentials are GGA-PBE-HGH and GGA-PBE-Troullier Martins (TM) and a good agreement was found with previous theoretical and experimental data. The segregation energy calculations show that the segregation of Sn at the sites of symmetric tilt grain boundary plane is unfavourable, while it is favourable at the sites of the first plane parallel to the grain boundary plane. However, for the other planes, the segregation is unfavourable. From an energetic point of view, it is not appropriate for the Sn to replace the Zr atom in the studied grain boundary, which was demonstrated by the charge density maps.

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Diffusion of point defects, nucleation of dislocation loops, and effect of hydrogen in hcp-Zr: Ab initio and classical simulations

Cited by 68 publications

References 58 publications

Nano-scale chemical evolution in a proton-and neutron-irradiated Zr alloy

Nano-scale chemical evolution in a proton-and neutron-irradiated Zr alloy

Molecular Level Characterization of the Structure and Interactions in Peptide‐Functionalized Metal–Organic Frameworks

<i>Ab Initio</i> Study of Tin Segregation in Zirconium at the Σ17(0̅337) Tilt Grain Boundary

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