Abstract
Defects, defect interactions, and defect dynamics in solids created by fast neutrons are known to have significant impact on the performance and lifetime of structural materials. A fundamental understanding of the radiation damage effects in solids is therefore of great importance in assisting the development of improved materials - materials with ultrahigh strength, toughness, and radiation resistance. In this presentation, we show our recent theoretical investigation on the magnetic structure evolution of bulk iron in the region of the radiation defects. We applied a linear scaling ab-initio method based on density functional theory with local spin density approximation, namely the locally self-consistent multiple scattering method (LSMS), to the study of magnetic moment distributions in a cascade at the damage peak and for a series of time steps as the interstitials and vacancies recombined. Atomic positions correspond to those in a low energy cascade in a 10000 atom sample, in which the primary damage state and the evolution of all defects produced were simulated using molecular dynamics with empirical, embedded-atom inter-atomic potentials. We will discuss how a region of affected moments expands and then recedes in response to a cascade evolution.
Original language | English |
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Article number | 07E120 |
Journal | Journal of Applied Physics |
Volume | 109 |
Issue number | 7 |
DOIs | |
State | Published - Apr 1 2011 |
Funding
This research was performed at Oak Ridge National Laboratory (ORNL) and is based upon work supported as part of the Center for Defect Physics in Structural Materials (CDP), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. This research used resources of the Oak Ridge Leadership Computing Facility at ORNL, which is supported by the Office of Science of the Department of Energy under contract DE-AC05-00OR22725.