Deducing density and strength of nanocrystalline Ta and diamond under extreme conditions from X‐ray diffraction. (21st January 2019)

• Record Type: Journal Article
• Authors: Zhang, Y. Y.; Tang, M. X.; Cai, Y.; E, J. C.; Luo, S. N.
• Is Part Of: Journal of synchrotron radiation. Volume 26:Part 2(2019)
• Page Start: 413
• Page End: 421
• Publication Date: 2019-01-21
• Subjects: high‐pressure density and strength -- nanocrystalline Ta -- diamond -- diamond anvil cell compression -- shock compression -- X‐ray diffraction simulation -- molecular dynamics; Synchrotron radiation -- Periodicals; Free electron lasers -- Periodicals; 539.73505
• DOI: 10.1107/S1600577518017216
• Languages: English
• ISSNs: 0909-0495

Abstract

Abstract : A methodology of deducing strength and density of polycrystalline tantalum and diamond under extreme compression conditions from two‐dimensional X‐ray diffraction patterns is examined rigorously with large‐scale molecular dynamics and X‐ray diffraction simulations. Abstract : In situ X‐ray diffraction with advanced X‐ray sources offers unique opportunities for investigating materials properties under extreme conditions such as shock‐wave loading. Here, Singh's theory for deducing high‐pressure density and strength from two‐dimensional (2D) diffraction patterns is rigorously examined with large‐scale molecular dynamics simulations of isothermal compression and shock‐wave compression. Two representative solids are explored: nanocrystalline Ta and diamond. Analysis of simulated 2D X‐ray diffraction patterns is compared against direct molecular dynamics simulation results. Singh's method is highly accurate for density measurement (within 1%) and reasonable for strength measurement (within 10%), and can be used for such measurements on nanocrystalline and polycrystalline solids under extreme conditions ( e.g. in the megabar regime).