DISLOCATION DISTRIBUTION IN DEFORMED GERMANIUM

Abstract

The dislocation distribution in germanium single crystals deformed at 520 °C and cooled under load was investigated by electron transmission and etch pitting at different stages of the stress–strain curve. Contrary to the findings of previous investigators, the Peierls force was not found to be strong enough to line up dislocations in close-packed directions. The dislocation arrangement observed in Ge is rather similar to that found in f.c.c. crystals in which a rearrangement of dislocations was prevented. In particular, dislocations have predominantly edge character, lie in stage I mainly in the primary slip planes, interact with dislocations on cross slip planes, and form braids, etc. Forest dislocations are found concentrated in zones almost parallel to certain primary slip planes which primary dislocations seem to avoid.