Transmission Electron Microscopy of the Configuration of Cracks and the Defect Structure Near to Cracks in Si

摘要

A focused ion beam technique was applied to preparing foil specimens for transmission electron microscopy and cracks and the defect structures near the cracks were observed. Cracks were introduced by Vickers indentation in Si at room temperature. Below ductile-brittle transition temperature (DBTT), cracks were of cleavage type and very straight, while at DBTT, cracks were zigzagged. Many small dislocation loops were observed in the wake of the crack which has propagated at DBTT.