$($a$)/(2)[()/($bar$)(1)01]->($a$)/(6)[()/($bar$)(2)11]+($a$)/(6)[()/($bar$)(1)/($b$)$ar $(1)2]$

The two Shockley partials repel one another leaving a stacking fault in between them.

Consider a fcc solid with a shear modulus of $100$ GPa $.$ The burgers vector of the

Shockley partials is $0\mathrm{.}20$ nm $.$ Determine the stacking fault energy, in m$($J$)/($m$^(2)),$ if the partial

dislocations are separated by $12\mathrm{.}7$ nm $.$