INVERSION OF NONPERIODIC WAVE-FIELDS TO DETERMINE LOCALIZED DEFECT STRUCTURE

A methodology for obtaining high-resolution crystal structure potentia l distributions from electron microscope images of defects is examined using image simulation methods. The technique is based on the inversi on of the multislice procedure when extended to nonperiodic potentials , The sensitivity of the method to the defect model and position in th e crystal is examined briefly with the preliminary conclusion that thi s should not severely limit the applicability of the method. The major impediment for the successful experimental application of the method to the detection and structure determination of single, isolated self- interstitial defects in silicon is likely to be the preparation and fi xation of the surfaces of the specimen.