Fig. 4
Dislocation motion via nanoscale segment detrapping mechanism. a Correlated nanoscale processes for a leading partial dislocation (white color) in a sample with Ta = 950 K. The applied temperature and shear stress are 300 K and 300 MPa, respectively. The swept areas between two neighboring snapshots/instants when the dislocation settles down briefly without motion (e.g., 20 and 60 ps) are highlighted in red. b–e The calculated minimum energy path of a nanoscale segment detrapping process, for a sample with Ta = 950 K and subject to a local shear stress of 400 MPa. See Methods for calculation details. Reaction coordinates in b is the scaled hyperspace arc length. c shows the initial configuration with a curved leading partial dislocation (the blue tube). d shows the configuration corresponding to the highest saddle point in b, and e shows the final configuration. For c–e, surface atoms are colored according to their positions along the axial direction and white atoms represent the complex stacking fault. The activated process of nanoscale segment detrapping during dislocation stick-slip motion is highlighted by the swept area as colored in red, based on the magnitude of atomic displacements along the axial direction. Numbers on the colorbar are in unit of Å
