Atomic simulations of (101¯2), (101¯1) twinning and (101¯2) detwinning in magnesium.

(101¯2) and (101¯1) twinning and (101¯2) detwinning for Mg were investigated from the viewpoint of mobility of twinning dislocations and atomic shuffling. First-principles calculations suggested that the twinning dislocations glide more readily for the (101¯1) twinning than for the (101¯2) twinning. However, this conflicts with the experimental fact of easier (101¯2) twin formation. On the other hand, molecular dynamics simulations showed that the atomic shuffling was more activated for the (101¯2) twinning than for the(101¯1) twinning, which corresponds to the experimental fact. Therefore, it is suggested that the rate-controlling process for the twin formation is the atomic shuffling. Moreover, the calculations and simulations showed that the twinning dislocations glide more readily for the (101¯2) detwinning than for the (101¯2) twinning, whereas the atomic shuffling is less activated for the detwinning, suggesting that the detwinning occurs easily but is unstable, resulting in easy repetition of twinning-detwinning.