A study was made of the atomic structures of single dislocations and dislocation fronts, in recrystallized β-phase samples, by using high-resolution transmission electron microscopic images of edge-on defects. The Burgers vectors of the defects were determined on the images. The structural units and the core compositions of the defects were obtained by analysing the image contrast. Single 30° Si (glissile) or 30° C (glissile) dislocations were emitted during the recrystallization of β-SiC above 1900C. Their structural units confirmed the model proposed for elementary and compound semiconductors. The dislocation fronts which glided under thermal or thermodynamic stresses consisted of pile-ups of different 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>. The structural units of the dislocation fronts were due to a reconstruction of the structural units which were characteristic of the 90° and 30° structural units. The probability of formation of the dislocation fronts was found to be 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