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

The composition and orientation of the phases nucleating on a single crysta lline substrate during MOCVD of complex oxides are governed by thermodynami cs, growth kinetics, the structures of the substrate material and growing c ompounds. We demonstrate the importance of the formation of coherent interf aces for the stabilization of otherwise non-equilibrium oxide phases. The s ystematic analysis of experimental results (e.g. HREM study of coherent R2O 3 inclusions in RBa2Cu3O7 epitaxial films, epitaxial BaCu3O4 films on perov skite substrates of various orientations) shows that equilibrium relations in epitaxial thin films of complex oxides could remarkably differ from thos e of ceramics.