ABSTRACT
In the previous Chapters we have seen that there is a basic divide between macrotexture techniques (based on X-ray or neutron diffraction, Chapters 4 and 5 ) and microtexture techniques (based usually on electron diffraction, Chapters 7-1 l) , which relates to the scale of the inquiry and thence affects the nature of the primary output data. For macrotexture techniques the primary output is a profile of diffracted intensities which is characteristic of a large contiguous sample volume, whereas for microtexture - i.e. individual grain - techniques the primary output is a diffraction pattern from each sampled volume. Such a pattern embodies the complete crystallographic information inclusive of the orientation of the respective sampled volume, which usually is an individual crystallite wherein the orientation can be taken to be uniform. For the vast majority of microtexture work in both the TEM and §EM this type of pattern is a Kikuchi diffraction pattern. Other techniques occasionally used are selected area diffraction, which still has applications in TEM (Section 8.3) and the micro-Kossel technique in the SEM (Section 7.2).
