High-resolution transmission electron microscopic images were simulated for the core structures of ½[111] screw dislocations in body centered cubic metals to examine the possibility of determining the core structure experimentally by high-resolution transmission electron microscopy. Two types of cores were studied: a polarized core and an isotropic one. For the model crystals containing the screw dislocations with the two types of cores, high-resolution transmission electron microscopic images were calculated by a multi-slice method with the incident beam parallel to the [1¯10] direction that was perpendicular to the direction of the dislocation line. A qualitative difference between the images of the two types of cores was detected; for the isotropic core the image always possesses the two-fold symmetry, irrespective of the defocus value, while for the polarized core it did not. This fact suggested that high-resolution transmission electron microscopy experiments with the incident beam parallel to the [1¯10] direction could distinguish between the two types of core.

High-Resolution Transmission Electron Microscopy Image Simulation of Screw Dislocation Core Structures in Body Centered Cubic Metals. Y.Kamimura, K.Edagawa, M.Noda, K.Suzuki, S.Takeuchi: Materials Science and Engineering A, 2004, 387-389, 29-33