The atomic structures of single dislocations and of dislocation fronts in recrystallized β-phase material was studied by obtaining high-resolution transmission electron microscopic images of edge-on defects. The Burgers vectors of the defects were determined from the images. The structural units and core compositions of the defects were obtained by analyzing the image contrast. Single 30° Si(glissile) or 30° C(glissile) dislocations were emitted during recrystallization of the β-phase above 1900C. The structural unit confirmed a proposed model for elementary and compound semiconductors. The dislocation fronts, gliding under thermal or thermodynamic stresses, consisted of a pile-up of various Shockley partials. The dislocation triplets consisted of one 90° C(glissile) and two 30° Si(glissile) dislocations or vice versa. The core compositions of the 90° and 30° partial dislocations were also different in the fronts of 2 dislocations characterized by a Burgers vector equal to 1/12<112>ac. The structural units of the dislocation fronts were due to a reconstruction of structural units that were characteristic of the 90° and 30° structural units. The probability of formation of the dislocation fronts was independent of the core composition of the partials.

Atomic Structure and Core Composition of Partial Dislocations and Dislocation Fronts in β-SiC by High-Resolution Transmission Electron Microscopy. M.Lancin, C.Ragaru, C.Godon: Philosophical Magazine B, 2001, 81[11], 1633-47