2001 Volume 42 Issue 1 Pages 28-32
Emission of dislocations from a crack which propagated at the ductile-brittle transition temperature (DBTT) in Si was observed by combined use of focused-ion beam (FIB) technique and transmission electron microscopy (TEM). At the wake of a DBTT crack many dislocation lines and dislocation loops were observed, while a wake of a precrack introduced at room temperature, no dislocations were observed. In addition, those glide dislocation lines which are emitted at the DBTT crack are smoothly curved, indicating that they can overcome easily the Peierls stress.