The buried interface of epitaxially grown α-Fe2O3(00▪1)/α-Al2O3(00▪1) was studied using ion-scattering techniques and high-resolution transmission electron microscopy. The results revealed the existence of disordering at the interface; attributed to misfit dislocations associated with lattice mismatch between the substrate and the film. Molecular dynamics (MD) calculations were carried out in order to understand the formation of misfit dislocations and the interface structural features. The calculations showed that misfit dislocations formed in the Al2O3 substrate and terminated at the interface; consistent with experimental observations. Snapshots of the atomic positions generated by the MD calculations were used in Monte Carlo simulations of the ion channeling experiments. The hitting probabilities determined from these simulations were compared with the experimental surface and interface peaks obtained from aligned Rutherford back-scattering spectra. The combination of MD, and ion scattering simulations with Rutherford back-scattering and high-resolution transmission electron microscopy measurements yielded promising results in understanding the interface structures of single crystal Fe2O3/Al2O3.

Misfit Dislocations at the Single-Crystal Fe2O3/Al2O3 Interface. S.Maheswaran, S.Thevuthasan, F.Gao, V.Shutthanandan, C.M.Wang, R.J.Smith: Physical Review B, 2005, 72[7], 075403 (7pp)