Dislocation kink-pair energetics and pencil glide in body-centered-cubic crystals - art. no. 075505

When body-centered-cubic crystals undergo plastic deformation, the slip pla nes are often noncrystallographic. By performing atomistic simulation on th e activation pathway of dislocation jumps in bcc iron, we show that the mai n reason for bcc crystals to exhibit this phenomenon is that one type of ki nk pair has significantly lower energy than all the other types on the same slip plane. Dislocation motion therefore cannot continue on the same slip plane, and the dislocation has to cross slip onto an intersecting slip plan e after each atomic jump. Thus in the long run, the average slip plane woul d be zigzag and noncrystallographic.