Simplified explicit expressions were presented to describe the elastic displacement field of a periodic family of misfit dislocations running parallel to the two free surfaces of an elastically isotropic plate. In the situation where the period tends to infinity, the use of these expressions proves to be quite valuable for investigating the change of the separation distance, S , between two partial dislocations as a function of the position of one partial and the orientation of the fault plane. For the two 30° Shockley partials of a dissociated screw dislocation in an ultra-thin Si plate, numerical results indicated that S

could change drastically. This property was confirmed in anisotropic elasticity for a dislocation located near the free surface of a semi-infinite crystal. The results emphasize that particular attention should be paid to precise measurement of the local thickness and positions of the partials in weak beam or high resolution transmission electron microscopy experiments.

A Dissociated Dislocation in an Ultra-Thin Silicon Plate. S.Youssef, R.Bonnet: Philosophical Magazine, 2006, 86[20], 3077-88