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

Microstructure of Ag/BaTiO3 Films Grown on MgO(100) Substrate Under External Electric Field. M.J.Zhuo, X.L.Ma: Philosophical Magazine, 2007, 87[32], 5117-28