Plan-view observation of crack tips by focused ion beam/transmission electron microscopy

Cracks were introduced in a Si bulk single crystal by a Vickers indentation and foil specimens which contain the cracks in the plane of foil were prepared using a focused ion beam technique. The configuration of the cracks and the defect structures near the indentation were observed by transmission electron microscopy at 1 MV. The cracks were classified into two groups, a half penny crack and a lateral crack. The emission of dislocations near the crack tips was observed by both an in-situ heating and a post mortem heating experiment.