A new model for the transition was proposed which was based upon the Kosterlitz-Thouless concept of dislocation screening. In this model, thermal fluctuations which were assisted by the applied stress promoted the spontaneous generation of dislocations, and the instability occurred well below the melting point. In the limit of zero stress, the model reduced to the Kosterlitz-Thouless theory for the transition. In the limit of zero temperature, the Rice-Thomson result for the transition was obtained.

A Cooperative Dislocation Generation Instability - the Brittle-to-Ductile Transition. M.Khanta, V.Vitek, D.P.Pope: Solid State Phenomena, 1995, 42-43, 227-36