Mechanical heterogeneity in nanoscale films of liquid silica.
Molecular dynamics simulations are carried out for slabs of silica liquid with thicknesses between 1 and 3 nm . A local analysis of the Born contribution to the elastic modulus, CB, shows that the elasticity is not uniform throughout the slabs--CB is identical to that of bulk silica in the slab interior, but CB is larger at the slab edges. The larger CB at the slab edges is due to a distinct atomic level structure characterized by larger density, larger concentration of more highly coordinated ions, and smaller silica rings.
Department of Chemical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Daniel J
DJ
Lacks
Michael-Paul
MP
Robinson