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By applying an electric field parallel to the substrate surface, highly ordered Ag nanoparticles were homogeneously embedded in BaTiO3 (BTO) films grown on a MgO(100) substrate. Transmission electron microscopy studies show that the BTO film is [100]-oriented. The general crystallographic orientation relationships between the composite film and MgO substrate are [100]BTO//[100]Ag//[100]MgO and (010)BTO//(010)Ag//(010)MgO. However, in films grown without an external electric field, Ag particles grow with random orientations and the BTO matrix is polycrystalline. Thus, electric fields are thought to meliorate the quality of the films by changing the growth orientation. In addition, the BTO matrix and Ag particles were found to be multiply twinned from studies on cross-sectional specimens. The contribution is discussed of Ag particles with ordered growth orientation and the large amount of BTO microtwins with higher dielectric constant to the improved optical properties of the as-prepared composite films. [ABSTRACT FROM AUTHOR]

The microstructural characteristics of misfit dislocations at the interface between La 0.9 Sr 0.1 MnO 3 films and vicinal SrTiO 3 substrates have been studied by transmission electron microscopy. The misfit dislocations were determined to be edge type with Burgers vector Owing to the inclination of the substrate, the dislocation line along the miscut direction of the substrate is rotated. The deviation angle of the dislocation line away from the miscut direction of the substrate varies with the miscut angle. As a result, the dislocation arrays at the interface form a parallelogram dislocation network rather than an orthogonal network. A simple explanation of the misfit dislocation reaction with the step for the film on a vicinal substrate is proposed to interpret the rotation of the dislocation line along the miscut direction. [ABSTRACT FROM AUTHOR]

Thin films of orthorhombic La0.9Sr0.1MnO3, have been grown by computer-controlled laser molecular-beam epitaxy on SrTiO3(001) substrate and vicinal SrTiO3(001) substrates. Electron diffractions and high-resolution imaging reveal that the as-received thin films with thickness of 300 nm are epitaxially grown on the substrates. The microstructures in the film grown on SrTiO3(001) substrate are clarified in terms of the oriented microdomains, while the films on vicinal SrTiO3(001) substrates are predominated by a single [101]-oriented growth, which provides a useful routine for a design of preferred physical properties. Based on the minimization of surface energy, the mechanism of such a single domain formation is proposed. [ABSTRACT FROM AUTHOR]