Morphology of pyramidal screw dislocations in Mg

Itakura, Mitsuhiro  ; Kaburaki, Hideo; Yamaguchi, Masatake   ; Tsuru, Tomohito   

When dislocations dissociate, generalized stackingfault energy landscape determines the dissociation plane and thedissociation width. For the case of pyramidal dislocations in Mg, twoinequivalent slip planes are associated with one Burgers vector, andthe determination of the morphology of the split dislocation core ishighly non-trivial problem. Based on the first-principles calculationsof stacking fault energy of pyramidal planes and structural relaxationof dislocation core, we present unique properties of pyramidaldislocations in Mg.