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Fracture of Sub‐20nm Ultrathin Gold Nanowires
Author(s) -
Lu Yang,
Song Jun,
Huang Jian Yu,
Lou Jun
Publication year - 2011
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201101224
Subject(s) - materials science , nucleation , fracture (geology) , nanowire , ductility (earth science) , composite material , dislocation , high resolution transmission electron microscopy , nanoscopic scale , brittleness , transmission electron microscopy , shear (geology) , nanotechnology , chemistry , creep , organic chemistry
Fracture of metals at the nanoscale and corresponding failure mechanisms have recently attracted considerable interest. However, quantitative in situ fracture experiments of nanoscale metals are rarely reported. Here it is shown that, under uni‐axial tensile loading, single crystalline ultrathin gold nanowires may fracture in two modes, displaying distinctively different fracture morphologies and ductility. In situ high resolution transmission electron microscopy (HRTEM) studies suggest that the unexpected brittle‐like fracture was closely related to the observed twin structures, which is very different from surface dislocation nucleation/propagation mediated mechanism in ductile fracture mode. Molecular dynamics (MD) simulations further reveal the processes of shear‐induced twin formation and damage initiation at the twin structure/free surface interface, confirming the experimentally observed differences in fracture morphology and ductility. Finally, a fracture criterion based on competition between twin formation and surface dislocation nucleation/propagation as a function of misalignment angle is discussed.