DEFECT IMAGING AND CHANNELING STUDIES USING CHANNELING SCANNING-TRANSMISSION ION MICROSCOPY

The technique of channeling scanning transmission ion microscopy (CSTI M) can be used to produce images of individual crystal defects (such a s dislocations and stacking faults) using the scanned, focused ion bea m from a nuclear microprobe. As well as offering a new method for stud ies of crystal defects, this technique can be used to investigate the effects of single defects on the channeling process. This paper descri bes some of the characteristics of the CSTIM technique, such as its ab ility to image large areas of a crystal, to image under thin, amorphou s surface layers and to image defects on the back surface of 50 mu m t hick crystals. An unexpected effect seen in CSTIM images of stacking f aults, namely the ability of faults to convert ions on blocked traject ories into well-channeled ones, is described to illustrate the use of CSTIM for channeled ion-defect interaction studies.