An atomistic study was used to characterize the formation and extension of nano-sized cracks. By using atomistic reaction pathway calculations, the energetics were determined which governed the brittle and ductile responses of an atomically sharp crack in silicon. These involved the competing processes of cleavage bond-breaking, dislocation emission and amorphization via the formation of five- and seven-membered rings. It was shown that the nanoscale fracture process depended sensitively upon the system size and loading method.

Mechanics of Nanocrack - Fracture, Dislocation Emission, and Amorphization. S.Huang, S.Zhang, T.Belytschko, S.S.Terdalkar, T.Zhu: Journal of the Mechanics and Physics of Solids, 2009, 57[5], 840-50