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This content will become publicly available on April 25, 2019

Title: Characterizing single isolated radiation-damage events from molecular dynamics via virtual diffraction methods

In this study, the evolution and characterization of single-isolated-ion-strikes are investigated by combining atomistic simulations with selected-area electron diffraction (SAED) patterns generated from these simulations. Five molecular dynamics simulations are performed for a single 20 keV primary knock-on atom in bulk crystalline Si. The resulting cascade damage is characterized in two complementary ways. First, the individual cascade events are conventionally quantified through the evolution of the number of defects and the atomic (volumetric) strain associated with these defect structures. These results show that (i) the radiation damage produced is consistent with the Norgett, Robinson, and Torrens model of damage production and (ii) there is a net positive volumetric strain associated with the cascade structures. Second, virtual SAED patterns are generated for the resulting cascade-damaged structures along several zone axes. The analysis of the corresponding diffraction patterns shows the SAED spots approximately doubling in size, on average, due to broadening induced by the defect structures. Furthermore, the SAED spots are observed to exhibit an average radial outward shift between 0.33% and 0.87% depending on the zone axis. Finally, this characterization approach, as utilized here, is a preliminary investigation in developing methodologies and opportunities to link experimental observations with atomistic simulations tomore » elucidate microstructural damage states.« less
Authors:
 [1] ; ORCiD logo [2] ;  [3] ;  [4] ;  [5] ;  [1] ; ORCiD logo [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Carleton College, Northfield, MN (United States). Department of Computer Science
  3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  4. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rensselaer Polytechnic Inst., Troy, NY (United States). Department of Mechanical, Aerospace, and Nuclear Engineering
  5. Rensselaer Polytechnic Inst., Troy, NY (United States). Department of Mechanical, Aerospace, and Nuclear Engineering
Publication Date:
Report Number(s):
SAND-2018-4391J
Journal ID: ISSN 0021-8979; 662638
Grant/Contract Number:
AC04-94AL85000; NA0003525
Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 123; Journal Issue: 16; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
OSTI Identifier:
1441473