A. E. Sand S. L. Dudarev K. Nordlund
Recent experiments on in situ high-energy self-ion irradiation of tungsten (W) show the occurrence of unusual cascade damage effects resulting from single-ion impacts, shedding light on the nature of radiation damage expected in the tungsten components of a fusion reactor. In this paper, we investigate the dynamics of defect production in 150 keV c…
PublishedS.L. Dudarev
Density functional theory models developed over the past decade provide unique information about the structure of nanoscale defects produced by irradiation and about the nature of short-range interaction between radiation defects, clustering of defects, and their migration pathways. These ab initio models, involving no experimental input parameters…
PublishedM.Yu. Lavrentiev D. Nguyen-Manh J. Wrobel S.L. Dudarev
We develop a Magnetic Cluster Expansion (MCE) model for binary bcc and fcc Fe–Cr alloys, as well as for fcc Fe-Ni alloys, and apply it to the investigation of magnetic properties of these alloys over a broad interval of concentrations, and over a broad interval of temperatures extending well over 1000 K. We show how an MCE-based Monte Carlo study…
PublishedD. Nguyen-Manh Pui-Wai Ma M.Yu. Lavrentiev S.L. Dudarev
The development of quantitative models for radiation damage effects in iron, iron alloys and steels, particularly for the high temperature properties of the alloys, requires understanding of magnetic interactions, which control the phase stability of ferritic-martensitic, ferritic, and austenitic steels. In this work, disordered magnetic configurat…
PublishedPui-Wai Ma S. L. Dudarev
We develop a generalized Langevin spin dynamics (GLSD) algorithm where both the longitudinal and transverse (rotational) degrees of freedom of atomic magnetic moments are treated as dynamic variables. This removes the fundamental limitation associated with the use of stochastic Landau-Lifshitz (sLL) equations, in which the magnitude of magnetic mom…
PublishedS.P. Fitzgerald S. Aubry S.L. Dudarev W. Cai
Frank-Read sources are among the most important examples of dislocation sources in crystals, and their operation facilitates dislocation multiplication and hence yield and plastic flow. Iron is known to become highly elastically-anisotropic as the alpha - gamma transition at 912 degrees centigrage is approached, a temperature regime of critical imp…
PublishedM.Yu. Lavrentiev K. Mergia M. Gjoka D. Nguyen-Manh G. Apostolopoulos S.L. Dudarev
We present a combined experimental and computational study of high-temperature magnetic properties of Fe-Cr alloys with chromium content up to about 20 at.%. Magnetic Cluster Expansion method is applied to model the magnetic properties of random Fe-Cr alloys, and in particular the Curie transition temperature, as functions of alloy composition. We …
PublishedD. Nguyen-Manh M.Yu. Lavrentiev M. Muzyk S.L. Dudarev
Generic materials-related problems foreseen in connection with the operation of a fusion power plant present a major challenge for the development of magnetically confined fusion as a commercial power generation option. In this review, we focus on the predictive capabilities of first-principles-based atomistic models for radiation defects and phase…
PublishedM.R. Gilbert S.L. Dudarev S. Zheng L.W. Packer J.-Ch. Sublet
The high-energy, high-intensity neutron fluxes produced by the fusion plasma will have a significant life-limiting impact on reactor components in both experimental and commercial fusion devices. As well as producing defects, the neutrons bombarding the materials initiate nuclear reactions, leading to transmutation of the elemental atoms. Products …
PublishedPui-Wai Ma S. L. Dudarev
We develop a dynamic spin-lattice-electron model for simulating the time-dependent evolution of coupled spin, atomic, and electronic degrees of freedom in a magnetic material. Using the model, we relate the dissipative parameters entering the Langevin equations for the lattice and spin degrees of freedom to the heat transfer coefficients of a pheno…
Published