Phase relations in thin epitaxial films of complex oxides prepared by MOCVD

The composition and orientation of the phases nucleating on a single crystalline substrate during MOCVD of complex oxides are governed by thermodynamics, growth kinetics, the structures of the substrate material and growing compounds. We demonstrate the importance of the formation of coherent interfaces for the stabilization of otherwise non-equilibrium oxide phases. The systematic analysis of experimental results (e.g. HREM study of coherent R2O3 inclusions in RBa2Cu3O7 epitaxial films, epitaxial BaCu3O4 films on perovskite substrates of various orientations) shows that equilibrium relations in epitaxial thin films of complex oxides could remarkably differ from those of ceramics. (orig.)