Undulating slip in Laves phase and implications for deformation in brittle materials

By combining density-functional theory calculations and aberration-corrected transmission electron microscopy, dislocations in Laves phase (a typical complex intermetallic compound) are shown to slip in an undulating path. During the slip, the dislocation cores jump up and down between a weakly bound plane and an adjacent strongly bound plane for gliding and atomic shuffling, respectively. This is different from the conventional slip process in simple metals, which is continuous within a single plane, as described in the paradigm of the generalized stacking fault energy.