Birefringence, x-ray topography and electron microscope examination of the plastic deformation of diamond

Publisher Website
Google Scholar
Abstract
The defect structures of types I, II A and II B diamonds were examined by the techniques of birefringence, x-ray projection and section topography and electron microscopy. It is suggested that the higher critical resolved shear stresses required to plastically deform type I diamonds compared with type II diamonds are due to the differences in the initial defect distribution in the two types of diamond. Type I diamonds have an extremely low dislocation density and a high density of coherent nitrogen precipitates in the cube planes, whereas type II diamonds have a high dislocation density (in excess of 107 lines per cm2) with no nitrogen platelets present. There was no evidence for the relief of internal strains by heating the diamonds to 1800°c, although strains at surface scratches appeared to have been decreased by the heat treatment.

This publication has 18 references indexed in Scilit: