Direct observations of room-temperature dislocation plasticity in single crystalline samples were presented. Previous studies had shown that phase transformation and fracture were the relevant mechanisms of deformation in Si. In contrast, using in-situ nano-indentation in a transmission electron microscope dislocation nucleation and metal-like flow were found. The results of finite-element modelling suggested that the presence of free surfaces in the present unique sample geometry led to preferential surface nucleation of dislocations and the suppression of phase transformation.

Room Temperature Dislocation Plasticity in Silicon. A.M.Minor, E.T.Lilleodden, M.Jin, E.A.Stach, D.C.Chrzan, J.W.Morris: Philosophical Magazine, 2005, 85[2-3], 323-30