Interface accommodation mechanism for weakly interacting epitaxial systems

摘要

We report here an interface accommodation mechanism observed by using in situ grazing incidence X-ray diffraction in the very early stages of Ge epitaxial growth on SrTiO_3. This mechanism leads to interface-localized misfit accommodation and involves two regimes: very early dislocation emergence followed by a damped collective oscillatory lattice parameter evolution. We show that this behavior is compatible with the simplest nonlinear Frenkel-Kontorova model assuming the weak elastic-chain/ substrate interaction.