The deposition of BaTiO3 thin films onto (001) SrTiO3 substrates was studied. The critical thickness at which the growth mechanism changed, from epitaxial growth without defects to pseudomorphic growth with the introduction of misfit dislocations, had previously been estimated to be about 4 monolayers. Molecular dynamics simulations were performed in order to clarify the formation mechanism of these misfit dislocations. When the misfit dislocations formed, they dissociated into a (101) stacking fault, and 1 partial dislocation migrated to the interface. The interface energy was lowered in spite of stacking-fault formation. The atomistic structure of the stacking fault on the (101) plane consisted of one O layer in the center and - in the next layer - Ba and Ti atoms which faced each other. This was consistent with high-resolution transmission electron microscopic observations.

Formation of Stacking Faults from Misfit Dislocations at the BaTiO3/SrTiO3 Interface Simulated by Molecular Dynamics. W.Wunderlich, M.Fujimoto, H.Ohsato: Materials Science and Engineering A, 2001, 309-310, 148-51