Crack tip dislocations revealed by electron tomography in silicon single crystal. Masaki Tanaka a*, Kenji Higashida a, Kenji Kaneko a b Satoshi Hata c, and Masatoshi Mitsuhara c a Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan b JST-CREST, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan c Department of Engineering Sciences for Electronics and Materials, Kyushu University, 6-1 Kasuga koen, Kasuga, Fukuoka 816-8580, Japan Received 10 June 2008; revised 25 June 2008; accepted 25 June 2008 Available online 6 July 2008

Crack tip dislocations in silicon single crystals have been observed by a combination of annular dark-field scanning transmission electron microscopy and computed tomography. A series of images was acquired by maintaining the diffraction vector parallel to that of crack propagation to achieve sharp images of the dislocations. The observed dislocations were reconstructed by a filtered back-projection, and exhibited three-dimensional configurations of overlaid dislocations around the crack tip. 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Keywords: Electron tomography; Fracture; Dislocations; Transmission electron microscopy; Scanning transmission electron microscopy