The dislocation distribution in plastically deformed magnesium oxide

Abstract

A detailed picture of the dislocation distribution within plastically deformed magnesium oxide has been obtained, using etch pitting techniques and transmission electron microscopy. Evidence for some rearrangement of the dislocations during thinning of the crystals is found. The dislocation structure of slip bands is qualitatively similar in crystals deformed within the temperature range 80 to 800 °K. The most prominent feature of the slip bands is the presence of elongated loops of dislocation, the majority of which are in the edge orientation. Although an increase in loop density is found at slip band intersections these are not the main sites for their production. The proposed mechanisms for loop formation are considered.