scholarly journals Molecular dynamics simulations of grain boundaries in thin nanocrystalline silicon films

1997 ◽  
Author(s):  
G.P. Berman ◽  
G.D. Doolen ◽  
R. Mainieri ◽  
D.K. Campbell ◽  
V.A. Luchnikov
1997 ◽  
Vol 472 ◽  
Author(s):  
P. Keblinski ◽  
S. R. Phillpot ◽  
D. Wolf ◽  
H. Gleiter

ABSTRACTMolecular-dynamics simulations were used to synthesize nanocrystalline silicon with a grain size of up to 75 Å by crystallization of randomly misoriented crystalline seeds from the melt. The structures of the highly-constrained interfaces in the nanocrystal were found to be essentially indistinguishable from those of high-energy bicrystalline grain boundaries (GBs) and similar to the structure of amorphous silicon. Despite disorder, these GBs exhibit predominantly four-coordinated (sp3-like) atoms and therefore have very few dangling bonds. By contrast, the majority of the atoms in high-energy bicrystalline GBs in diamond are three-coordinated (sp2-like). Despite the large fraction of three-coordinated GB carbon atoms, they are rather poorly connected amongst themselves, thus likely preventing any type of graphite-like electrical conduction through the GBs.


2018 ◽  
Vol 20 (20) ◽  
pp. 13944-13951 ◽  
Author(s):  
Pedro Augusto Franco Pinheiro Moreira ◽  
Roberto Gomes de Aguiar Veiga ◽  
Ingrid de Almeida Ribeiro ◽  
Rodrigo Freitas ◽  
Julian Helfferich ◽  
...  

First-principles and classical molecular dynamics simulations show that diffusion of water molecules at pre-melted grain boundaries in ice is glassy-like, showing sub-diffusive behavior.


2009 ◽  
Vol 633-634 ◽  
pp. 31-38
Author(s):  
Ajing Cao

We have previously reported that the fracture behavior of nanocrystalline (NC) Ni is via the nucleation and coalescence of nano-voids at grain boundaries and triple junctions, resulting in intergranular failure mode. Here we show in large-scale molecular dynamics simulations that partial-dislocation-mediated plasticity is dominant in NC Cu with grain size as small as ~ 10 nanometers. The simulated results show that NC Cu can accommodate large plastic strains without cracking or creating damage in the grain interior or grain boundaries, revealing their intrinsic ductile properties compared with NC Ni. These results point out different failure mechanisms of the two face-centered-cubic (FCC) metals subject to uniaxial tensile loading. The insight gained in the computational experiments could explain the good plasticity found in NC Cu not seen in Ni so far.


Sign in / Sign up

Export Citation Format

Share Document