This quantification method was based upon the digital comparison of images which were recorded at increasing beam exposure times while other conditions were kept constant. Difference images that were calculated from the original images revealed whether damage occurred preferentially at extended defects such as internal interfaces. Further analysis indicated how long the specimen could be imaged before irradiation damage affected the structure. The value of the method was demonstrated by applying it to high-resolution transmission electron microscopy of the interface between Cu and sapphire, and of the  = 3 (111) twin boundary in NiAl. Both were imaged by using 1250keV high-resolution transmission electron microscopy. It was concluded that such images should be recorded during the first 600s of observation in order to avoid the creation of irradiation-related artefacts.

G.Dehm, K.Nadarzinski, F.Ernst, M.Ruhle: Ultramicroscopy, 1996, 63[1], 49-55