Dissociation of an FCC perfect dislocation
= Dissociation of an FCC perfect dislocation
{c}
A perfect vector $a\langle110\rangle/2$ can separate into two in-plane Shockley partials bounding a stacking-fault ribbon. The sum of squared Burgers magnitudes falls from $a^2/2$ to $a^2/3$, reducing the simplest elastic line-energy estimate, while stacking-fault area costs energy.