When α-Fe2O3 thin films were deposited onto α-Al2O3(00▪1) substrates by using O plasma-assisted molecular beam epitaxy, a periodic distribution of basal dislocations formed due to lattice mismatch along the interfaces. High-resolution transmission electron microscopy showed, when observed along the <11▪0> zone axis, that these dislocations lay at the interface, about 7.0nm apart. Molecular dynamics simulations were performed in order to understand the formation of misfit dislocations and the interface structural features in the Fe2O3/Al2O3 system. It was found that the misfit dislocations were mainly formed in Al2O3 substrates, with a Burgers vector of 1/3<11▪0>, and terminated at the interfaces; consistent with previous experimental observations. These dislocations could dissociate into 2 partial dislocations, with Burgers vectors of 1/3<10▪0> and 1/3<01▪0>, by forming stacking faults on (00▪1) planes. The core structures of the misfit dislocations in semi-coherent interfaces were analyzed in detail, and the misfit dislocations were found to have narrow cores in the plane of the interfaces.

Atomic-Level Simulations of Misfit Dislocations at the Interface of Fe2O3/Al2O3 System. F.Gao, C.M.Wang, S.Maheswaran, S.Thevuthasan: Nuclear Instruments and Methods in Physics Research B, 2003, 207[1], 63-71