First-principles calculation of the elastic dipole tensor of a point defect: Application to hydrogen in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>α</mml:mi></mml:math>-zirconium

Nazarov, Roman; Majevadia, J S; Patel, Mitesh; Wenman, M.R.; Balint, Daniel S.; Neugebauer, Jörg; Sutton, A. P.

doi:10.1103/physrevb.94.241112

Cited by 26 publications

(26 citation statements)

References 34 publications

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“…the region which has to be excluded from the displacement fit or the restoration zone for the Kanzaki forces. This is penalizing for ab initio calculations, even for point-defects as simple as the H solute or the vacancy in hcp Zr [32,43]. Besides, the Kanzaki's technique requires additional calculations to obtain the defect-induced forces and to check that the forces entering the dipole definition are in the harmonic regime.…”

Section: Discussionmentioning

confidence: 99%

Elastic modeling of point-defects and their interaction

Clouet

Varvenne

Jourdan

2018

Computational Materials Science

110

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Different descriptions used to model a point-defect in an elastic continuum are reviewed. The emphasis is put on the elastic dipole approximation, which is shown to be equivalent to the infinitesimal Eshelby inclusion and to the infinitesimal dislocation loop. Knowing this elastic dipole, a second rank tensor fully characterizing the point-defect, one can directly obtain the long-range elastic field induced by the point-defect and its interaction with other elastic fields. The polarizability of the point-defect, resulting from the elastic dipole dependence with the applied strain, is also introduced. Parameterization of such an elastic model, either from experiments or from atomic simulations, is discussed. Different examples, like elastodiffusion and bias calculations, are finally considered to illustrate the usefulness of such an elastic model to describe the evolution of a point-defect in a external elastic field.

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Section: Discussionmentioning

confidence: 99%

Elastic modeling of point-defects and their interaction

Clouet

Varvenne

Jourdan

2018

Computational Materials Science

110

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“…The availability of such data is still relatively limited as the majority of density functional calcul ations of defects performed so far focused on the accurate evaluation of energies of defects [42][43][44][45], rather than on the evaluation of elastic properties of defects [7,8,27,29,46]. The relaxation volume of a Frenkel pair can be approximated by the sum of relaxation volumes of an SIA and a vacancy.…”

Section: Relaxation Volumes Of Point Defects In Bcc Transition Metalsmentioning

confidence: 99%

A multi-scale model for stresses, strains and swelling of reactor components under irradiation

et al. 2018

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Predicting strains, stresses and swelling in nuclear power plant components exposed to irradiation directly from the observed or computed defect and dislocation microstructure is a fundamental problem of fusion power plant design that has so far eluded a practical solution. We develop a model, free from parameters not accessible to direct evaluation or observation, that is able to provide estimates for irradiation-induced stresses and strains on a macroscopic scale, using information about the distribution of radiation defects produced by high-energy neutrons in the microstructure of materials. The model exploits the fact that elasticity equations involve no characteristic spatial scale, and hence admit a mathematical treatment that is an extension to that developed for the evaluation of elastic fields of defects on the nanoscale. In the analysis given below we use, as input, the radiation defect structure data derived from ab initio density functional calculations and large-scale molecular dynamics simulations of high-energy collision cascades. We show that strains, stresses and swelling can be evaluated using either integral equations, where the source function is given by the density of relaxation volumes of defects, or they can be computed from heterogeneous partial differential equations for the components of the stress tensor, where the density of body forces is proportional to the gradient of the density of relaxation volumes of defects. We perform a case study where strains and stresses are evaluated analytically and exactly, and develop a general finite element method implementation of the method, applicable to a broad range of predictive simulations of strains and stresses induced by irradiation in materials and components of any geometry in fission or fusion nuclear power plants.

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“…Refs. [40][41][42]), a local quantity of particular significance because it allows modelling the coupling of a point defect to the strain fields of isolated dislocations, e.g., in the manner prescribed by Ref. [43].…”

Section: Interstitial Sites and Segregation Energiesmentioning

confidence: 99%

Imeall: A computational framework for the calculation of the atomistic properties of grain boundaries

Lambert

Fekete

Kermode

et al. 2018

Computer Physics Communications

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a b s t r a c tWe describe the Imeall package for the calculation and indexing of atomistic properties of grain boundaries in materials. The package provides a structured database for the storage of atomistic structures and their associated properties, equipped with a programmable application interface to interatomic potential calculators. The database adopts a general indexing system that allows storing arbitrary grain boundary structures for any crystalline material. The usefulness of the Imeall package is demonstrated by computing, storing, and analysing relaxed grain boundary structures for a dense range of low index orientation axis symmetric tilt and twist boundaries in α-iron for various interatomic potentials. The package's capabilities are further demonstrated by carrying out automated structure generation, dislocation analysis, interstitial site detection, and impurity segregation energies across the grain boundary range. All computed atomistic properties are exposed via a web framework, providing open access to the grain boundary repository and the analytic tools suite. Program summaryProgram Title: Imeall Program Files doi: http://dx.doi.org/10.17632/nj77stc62b.1 Licensing provisions: Apache-2.0 Programming languages: python, fortran, javascript Nature of problem: Determining the minimum energy structure for a specific grain boundary and interatomic force field involves extensive searches in configuration space. Duplication of this effort should be avoided, and providing a unique database to gather the resulting structures is needed for this. Accurately cataloguing the chemical and electronic environments associated with the interface atoms in the grain boundary furthermore requires a useable interface between a database of grain boundary structures and an expandible set of interatomic potential calculators. Solution method: We introduce a standard indexing convention that allows the integration of grain boundary structures for arbitrary materials, generated by different users/research groups, into a normalised database that can be easily queried and used as a starting point for further research projects. The Imeall package accomplishes this by specifying a standard naming convention for the grain boundary database and by providing the software routines necessary to populate and query such a database, as well as an interface to interatomic calculators and analysis tools.

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First-principles calculation of the elastic dipole tensor of a point defect: Application to hydrogen inα-zirconium

Cited by 26 publications

References 34 publications

Elastic modeling of point-defects and their interaction

Elastic modeling of point-defects and their interaction

A multi-scale model for stresses, strains and swelling of reactor components under irradiation

Imeall: A computational framework for the calculation of the atomistic properties of grain boundaries

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