Dislocation motion around loaded notches in ice single-crystals

Synchrotron X-ray topography has been used to study dislocation behavior around notches in single-crystals of ice during in-situ deformation at a constant strain-rate. During deformation at - 8 degrees C a dislocation-depleted zone (DDZ) formed above the notch while a vertical array of dislocations formed below the notch. Modeling the interaction between basal plane dislocation loops and the notch stress field suggested that this DDZ arose from dislocations gliding completely through the specimen. Dislocation activity around the notch at -8 degrees C was much greater than that observed at -40 degrees C and -60 degrees C. (C) 2000 Elsevier Science B.V. All rights reserved.