Comment on the brittle-to-ductile transition: A cooperative dislocation generation instability; Dislocation dynamics and the strain-rate dependence of the transition temperature

A new theory by Khantha, Pope and Vitek (KPV) and Khantha, which attributes sharp brittle-to-ductile transitions (BDT) of the type observed in silicon to a cooperative Kosterlitz-Thouless instability for dislocation generation, is examined critically. Results of simulations relevant to the KPV model...