Abstract
Using an ab initio- based parametric dislocation dynamics approach we show that Shockley partials on successive glide planes greatly assist the widening of stacking faults (SFs) in Al and Ag. This effect is amplified when all trailing partials are pinned. Subsequent placement of Shockley partials on adjacent planes enhances further the widening of the SF width. In sharp contrast, dislocations with zero net Burgers vector across three successive planes form very compact cores in both Al and Ag, in agreement with recent experiments. (C) 2007 American Institute of Physics.