Fracture experiments of single silicon crystals reveal that after the critical fracture load is reached, the crack speed jumps from zero to 2km/sec, indicating that crack motion at lower speeds is forbidden. This contradicts classical continuum fracture theories predicting a continuously increasing crack speed with increasing load. Here we show that this threshold crack speed may be due to a localized phase transformation of the silicon lattice from 6-membered rings to a 5-7 double ring at the crack tip.
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy