Surface structure, morphology, and growth mechanism of Fe3O4/ZnO thin films

We have investigated the growth mechanism and surface structure of magnetite (Fe3O4) films grown on semiconducting ZnO substrates. Growth proceeds in a wetting layer plus island-mode and a later coalescence of islands, as was verified by electron diffraction, topography measurements of the surface, and the investigation of the microstructure. The typical (111) surface diffraction pattern magnetite is observed already at the early island growth stage. Due to the island-like growth mode, domain boundaries form upon coalescence of the islands. Twin boundaries have been evidenced between neighboring domains. Island growth enables partial relaxation of the misfit strain.