Large local deflections of a dynamic crack front induced by intrinsic dislocations in brittle single crystals.
We show that intrinsic dislocations in brittle single crystals can be a source of strong local perturbations along the crack path. A theoretical model was developed which predicts substantial crack front deflections. Investigating the crack surfaces in Si crystals with induced dislocation density of 10(9)-10(10) cm(-2) revealed a significant amount of crack front perturbations in the form of V-shaped grooves, which were completely missing in dislocation-free Si specimens. The measured depths of the perturbations were in the range of 2-20 nm and in excellent agreement with the theoretical model.
Shilo
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Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Sherman
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Beery
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Zolotoyabko
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