M. Yu. Lavrentiev J. S. Wróbel D. Nguyen-Manh S. L. Dudarev
A model lattice ab initio parameterized Heisenberg–Landau magnetic cluster expansion Hamiltonian spanning a broad range of alloy compositions and a large variety of chemical and magnetic configurations has been developed for face-centered cubic Fe–Ni alloys. The thermodynamic and magnetic properties of the alloys are explored using configuratio…
PublishedM. R. Gilbert S. Zheng R. Kemp L. W. Packer S. L. Dudarev J.-Ch. Sublet
A key goal for fusion materials modelling research is the development of predictive simulation models and capabilities to assess material performance under the neutron irradiation conditions expected in near-plasma regions of fusion reactor tokamaks. This paper presents computational results from the modelling of neutron fields in the latest concep…
PublishedS.L. Dudarev K. Arakawa X. Yi Z. Yao M.L. Jenkins M.R. Gilbert P.M. Derlet
Defect microstructures formed in ion-irradiated metals, for example iron or tungsten, often exhibit patterns of spatially ordered nano-scale dislocation loops. We show that such ordered dislocation loop structures may form spontaneously as a result of Brownian motion of loops, biased by the angular-dependent elastic interaction between the loops. P…
PublishedDuc Nguyen-Manh S.L. Dudarev
Properties of point defects resulting from the incorporation of inert-gas atoms in bcc tungsten are investigated systematically using first-principles density functional theory (DFT) calculations. The most stable configuration for the interstitial neon, argon, krypton and xenon atoms is the tetrahedral site, similarly to what was found earlier for …
PublishedD.R. Mason X. Yi M.A. Kirk S.L. Dudarev
Using in situ transmission electron microscopy (TEM), we have observed nanometre scale dislocation loops formed when an ultra-high-purity tungsten foil is irradiated with a very low fluence of self-ions. Analysis of the TEM images has revealed the largest loops to be predominantly of prismatic 1/2{111} type and of vacancy character. The formation o…
PublishedT. D. Swinburne S. L. Dudarev S. P. Fitzgerald M. R. Gilbert A. P. Sutton
Isolated kinks on thermally fluctuating 1/2 111 screw, 100 edge, and 1/2 111 edge dislocations in bcc iron are simulated under zero stress conditions using molecular dynamics (MD). Kinks are seen to perform stochastic motion in a potential landscape that depends on the dislocation character and geometry, and their motion provides fresh insight …
PublishedM.R. Gilbert S.L. Dudarev D.Nguyen-Manh L.W. Packer J-Ch. Sublet
In a fusion reactor materials will be subjected to significant fluxes of high-energy neutrons. As well as causing radiation damage, the neutrons also initiate nuclear reactions leading to changes in the chemical composition of materials (transmutation). Many of these reactions produce gases, particularly helium, which cause additional swelling and …
PublishedM-C Marinica Lisa Ventelon M R Gilbert L Proville S L Dudarev J Marian G Bencteux F Willaime
We have developed empirical interatomic potentials for studying radiation defects and dislocations in tungsten. The potentials use the embedded atom method formalism and are fitted to a mixed database, containing various experimentally measured properties of tungsten and ab initio formation energies of defects, as well as ab initio interatomic forc…
Published