On the mobility of dislocations in silicon by in situ straining in a high-voltage electron microscope

Deformation of intrinsic silicon single crystals has been investigated by in situ straining in a high-voltage electron microscope, at temperatures ranging from 520 to 615° and resolved shear stresses between 70 and 370 MPa. Deformation was observed to proceed through generation and glide of polygonal-shaped spiral dislocation loops. The mobilities of the screw and 60° straight segments of polygonal loops were measured directly and shown to be independent of their lengths down to about 0.4 μm. The activation energies for nucleation of double kinks are estimated for both types of dislocations.