A double dislocation pole model was proposed for deformation twinning in these lattices. Operation of the proposed twinning source occurred when a passing stress which presented a high energy barrier to the nucleation and growth of a twin was overcome by thermal activation. Orowan stress barriers were also involved in the twinning process, and tended to reduce the twin nucleation and growth rates.

S.G.Song, G.T.Gray: Philosophical Magazine A, 1995, 71[3], 661-70