A dissociated screw dislocation, parallel to the interface, was found in the epitaxial layer of a Si0.83Ge0.17/Si(001) system. It was shown that this dissociated screw dislocation, which consisted of two 30 partials, could relieve misfit strain energy. Also, the relieved misfit energy was proportional to the width of the stacking fault between the 2 partials dislocations.

X.Y.Wan, J.W.Liang, M.L.Liu, X.J.Jin: Physical Review B, 1997, 55[15], 9259-62