title: HVEM characterization of crack tip dislocations in silicon crystals.
abstract: Crack tip dislocations in silicon crystals have been studied using high voltage electron microscopy (HVEM). The dislocation images have been investigated by comparing the observed images to those that were simulated. Dislocation images were computed in the conditions g x b = 0, 1 or 2 (g: diffraction vector, b: Burgers vector). The characteristics of 60 degrees dislocations were examined in detail since these dislocations are not characterized only by the condition g x b = 0 criterion. The computed images were in good agreement with those observed by HVEM. Residual contrasts of 60 degrees dislocations under the condition g x b = 0 exhibited characteristic black-and-white contrasts, which can contribute to the characterization of the dislocations. Such characterization of dislocations is essential in order to clarify the dislocation mechanism which controls the fracture toughness of materials.
authors.affiliation: Department of Materials Science and Engineering, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. masaki@dera.zaiko.kyushu-u.ac.jp
authors.forename: Masaki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Kenji
authors.initials: K
authors.lastname: Higashida
mesh_terms: D003198:Computer Simulation; D003460:Crystallization; D046911:Macromolecular Substances / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission / Q000379:methods; D008958:Models, Molecular; D012825:Silicon / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D012825:Silicon