Defect Visualisation: Individual Defects

Abstract

This chapter will try to provide explanations and advice for the practising X-ray topographer. Much of the material has not previously been set down in print. The topics to be included have been selected with the needs of the inexperienced worker particularly in mind. Consequently, only the simpler techniques will be discussed: the section topograph, the projection topograph, and the scanning reflection topograph. However, X-ray topographers will surely want to read more comprehensive descriptions of the many techniques that have been devised over the years for various purposes, and to find out what results have been achieved using them. To do so, they may consult reviews by Armstrong [1] and Lang [2] (the latter preferably in the revised edition), and the monograph by Tanner [3]. Since X-ray topography is most widely known and practised as a non-destructive method for ‘seeing’ dislocations in crystals, a simply- worded review [4] spanning the topics of X-ray diffraction contrast from dislocations, other methods of observing dislocations, and the properties of dislocations themselves, may be found helpful.