Lomer edge dislocations formed at Ge/Si(001) hetero-interfaces were imaged with a 1.25MeV atomic-resolution electron microscope. The dislocation cores were primarily asymmetrical, and they were located close to the mean position of the interface, which was not structurally abrupt due to Ge–Si interdiffusion at the growth temperature of 550C. Structural models of the asymmetric dislocation cores could be derived directly from the experimental micrographs and image simulations were then used to validate the image interpretation.

Atomic-Scale Imaging of Asymmetric Lomer Dislocation Cores at the Ge/Si(001) Hetero-Interface. J.N.Stirman, P.A.Crozier, D.J.Smith, F.Phillipp, G.Brill, S.Sivananthan: Applied Physics Letters, 2004, 84[14], 2530-2