High-resolution electron microscopy was used to make a detailed study of 60 dislocations at the interface of atomic-layer molecular beam epitaxial samples. It was noted that their deformation fields interacted strongly with neighboring dislocations and led to an irregular spacing between the cores and dissociations. Bi-atomic Si steps were observed at the interface; but never within 60 dislocation cores. Computer image simulation, and elasticity calculations of the atomic displacement field, were used to determine the structure of the 60 dislocations. However, due to the Eshelby effect and to interaction with some neighboring dislocations, no theoretical model could explain the observations in many cases.

A.Vilà, A.Cornet, J.R.Morante, P.Ruterana, M.Loubradou, R.Bonnet: Journal of Applied Physics, 1996, 79[2], 676-81